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Demographics are not destiny, but steady and predictable changes to the electorate play an important role in defining the landscape of American politics. Most demographic groups have a political lean, so a group increasing or decreasing in size over time will tend to benefit one party or type of politics over another. The most well-known example is the growth of the nonwhite population in the United States, which—since nonwhites tend to lean heavily Democratic—is typically viewed as tilting the electoral terrain somewhat toward the Democrats over time as well as increasing the weight of nonwhite voters within the Democratic Party over time. But other changes are important, such as the decline of noncollege educated voters, particularly whites; the aging of the adult population; and the rise of new generations to replace older ones.

In this report, we will explore the effect of these changes on the demographic composition of the electorate and, especially, on the composition of the two major political parties. Reflecting the latter focus, this analysis will not focus on how many individuals from a given demographic group voted or will likely vote for the Democratic or Republican candidate in a particular election. Rather, it focuses on how many people who voted or are likely to vote for the Democratic or Republican candidate in a particular election belong to a given demographic group.

While the former tells us about the political leanings of a given group, the latter answers different questions. While size is not the sole determinant of a group’s influence within a party, it is a significant input and affects how parties formulate positions and present themselves to the electorate. As we head into the 2020 presidential primaries, we are bound to observe the effects of party composition on how candidates for the presidential nomination—especially Democratic candidates, due to their intense competition for voters—position themselves to garner primary votes from different demographic groups within their party.

Our investigation turns up a number of key findings that illuminate how significantly the compositions of the Democratic and Republican parties have changed over the years and are likely to change in the future. We show that the 2016 election was the most demographically divisive election in the past 36 years. The parties were more divided by age, race, and education than in any prior election in modern political history.

Reflecting these intensifying divisions, the parties were more compositionally different in 2016 than at any point in the prior 36 years. This election was the first presidential election white noncollege voters did not make up a plurality of both parties’ coalitions, with white college voters exceeding the share of white noncollege voters in the Democratic coalition.

Nonwhites will continue to grow as a share of both parties’ coalitions, especially Hispanics. We find that, by 2032, Hispanic voters will surpass black voters as the largest overall nonwhite voting group. And, by 2036, black voters will make up a larger share of the Democratic coalition than white noncollege voters.

On the other hand, we find that white voters will continue to decline through 2036 as a share of both the Republican and Democratic party coalitions, though this decline with be considerably quicker in fast-growing states such as Arizona and Texas that are already less white. White noncollege voters, in particular, are projected to decline rapidly as a share of both parties’ coalitions across all states through 2036, although the sharpest declines will, again, be in fast-growing states.

Generational changes will also be substantial. By 2036, Millennial and Generation Z voters—the two youngest generations—will be heavily represented in both the Democratic Party and Republican Party coalitions, while the influence of Baby Boomer and the Silent Generation voters—the two oldest generations—will radically decline. White Millennial and Generation Z voters, in particular, will develop a large presence in the Republican coalition and, combined with nonwhites, will give the GOP a new look in all states—even slow-growing ones such as Wisconsin and Ohio.

Finally, our data indicate that, while shifting turnout and support rates can be pivotal for winning elections, these changes are likely to have a relatively small impact on the overall makeup of the electorate and party coalitions in the future. Thus, most of the effect of demographic change on future party coalitions is already baked in and will reshape party coalitions—in a sense, whether these parties like it or not.

We use several different scenarios to investigate the potential future effect of demographic change on party composition in presidential years. They are:

The Democratic Party and the Republican Party are driven by different ideologies, they propose different kinds of policies, and they run different types of candidates for office. They also win different types of voters—voters with disparate demographic profiles. For example, as a group, those who vote for Democrats today are more racially diverse than those who vote for Republicans.

But how different are the parties demographically, and how have those differences evolved over time?

For this report, we developed two compositional gaps to answer those questions. They are metrics that allow us to look for compositional differences between the parties on certain demographic dimensions and observe how those differences have changed over time. Specifically, we developed race-education gaps to study how different the parties’ coalitions are along racial and education lines and age gaps to study how different the parties’ coalitions are along age lines.

As an example, let’s walk through generating a race-education gap for the 1980 presidential election. We would start by finding out what percent of those voting for the Democratic and Republican candidates fell into each relevant demographic group. For example, 76 percent of those who voted for the Republican candidate in that year were white noncollege compared to just 60 percent of those voting for the Democratic candidate. The next step would be finding the absolute difference between the composition of the parties for each demographic group we are concerned with and adding up all those differences. If one were to do that for 1980 presidential race with those five race-education groups mentioned above, the gap between the parties would be 42 points. (See Table 1 for details)

Generating these gaps for every presidential election between 1980 and today makes one thing clear: 2016 was the most demographically divisive presidential election in modern American history. The parties’ coalitions were more dissimilar in terms of their racial, educational, and age composition in 2016 than at any point in the previous 36 years.

Along racial and education lines, the parties’ coalitions have always been different. Between 1980 and 2004, the race-education gap was essentially stable in the high 30s and low 40s. However, in 2008, this gap grew to 62 points, dropped slightly in 2012 to 59 points, and then peaked at 63 points in 2016—the highest recorded gap over this period. This post-2004 jump was driven by changes in the voting behavior of nonwhite voters; the shift toward the Democratic Party among all groups between 2004 and 2008; and a notable increase in black turnout that rapidly diversified the Democratic coalition.

In fact, in the absence of those shifts, the race-education gap between the coalitions actually would have shrunk by about 6 points. Because the majority of white Americans vote Republican, their shift toward the Democratic candidate between 2004 and 2008 was actually working to reduce the race-education gap between the parties’ coalitions.

By contrast, the parties’ coalitions were once extremely similar in terms of age composition and have grown more divided over time. In 1980, the age gap between the parties was just 3 points. While this gap has been steadily increasing since the late 1980s, the post-2004 period is once again a time of change. The three largest increases in the age gap over this 36-year period all occurred after 2004.

Assuming that turnout and support rates stay the same, the demographic shifts occurring nationally will do little to close the gaps between the parties. As a result of these changes, we would expect the race-education gap and age gap to shrink about 2 points by 2036 (61 points and 28 points, respectively).

White voters

In 1980, almost 9 in 10 (87 percent) voters were white, including about 7 in 10 (69 percent) with no college degree and 18 percent with a college degree. Even at this time, the parties already were quite different. While whites made up the overwhelming majority (95 percent) of Republican voters, they were less than three-quarters (74 percent) of Democratic voters. Compared to Republican voters, a lower share of Democratic voters was white noncollege (76 percent versus 60 percent) and white college (19 percent versus 14 percent) in 1980.

In the intervening 36 years, two important trends reshaped the American electorate. First, immigration from Asia and Central and South America slowly diversified the voting population. Second, the educational attainment rates of young Americans increased, resulting in a marked rise in the number of Americans with a college education.

As a result of that first trend, about three-quarters (74 percent) of voters in 2016 were white. Almost 9 in 10 (88 percent) Republican voters in that election were white—a 7-point decline that mirrored the changes occurring in the overall voting population. By contrast, just 6 in 10 (60 percent) Democratic voters were white, a shift twice as large as the one observed among Republican voters and voters overall.

As a result of both trends, the percent of voters who were white noncollege dropped a dramatic 25 points over 36 years. By 2016, this group made up just 44 percent of voters.

Throughout this period, white noncollege voters have consistently made up a larger share of Republican voters. The gap between Republican and Democratic voters for this group was smallest in 1992 (64 percent versus 54 percent) and 1996 (62 percent versus 51 percent) but never dipped below a 10-point difference during this period.

(The solid lines are observed figures for the composition of the overall voting electorate, of Republican presidential voters, and of Democratic presidential voters through 2016; the dotted lines are projections through 2036 using our baseline model.)

By 2016, white noncollege voters made up 6 in 10 (60 percent) Republican voters but just 29 percent of Democratic voters. While the compositional shift for both parties has been dramatic, it has not been equal. The 36-year decline among Democrats (60 percent versus 29 percent) is almost twice as large as the decline among Republicans (76 percent versus 60 percent).

The story for white college voters is quite different. Despite an overall decline in the number of voters whom were white, rising educational attainment and higher turnout rates caused the share of white college voters to rise by 12 points over this period. White college voters made up 30 percent of voters in 2016. Compared to 1980, the share of white college voters in 2016 was 17-points higher among Democrats (14 percent versus 31 percent) and 9-points higher among Republicans (19 percent versus 28 percent).

This makes 2016 unique in a number of ways. First, the 2016 presidential election represents one of the largest compositional gaps between Republican and Democratic voters over this time period. In 2016, the number of voters who were white noncollege was 31-points higher among Republicans voters than Democratic voters. This compositional gap between Republicans and Democrats was part of a trend over the last two elections, with the next two largest gaps occurring in 2008 (62 percent versus 40 percent) and 2012 (60 percent versus 33 percent).

Second, it is the first election where white noncollege voters did not make up a plurality of both parties’ coalitions. Among those who voted Democratic, the share of white college voters (31 percent) was slightly larger than the share of white noncollege voters (29 percent). Furthermore, it is the first election where white college voters made up a plurality of Democratic voters. These are both significant milestones in the long-term trajectory of white voters.

Third, while white college voters consistently made up a larger share of Republican voters than they did Democratic voters between 1980 and 2012, this flipped in 2016. White college voters made up a slightly larger share of Democratic voters (31 percent) than Republican voters (28 percent) in that election.

Going forward into the future, these trends will continue. Holding turnout rates and voting preferences constant, we expect white voters to make up 72 percent of the electorate by 2020 and just 64 percent by 2036. Giving current voting patterns, we would expect more than 8 in 10 Republican voters to be white in 2020 (86 percent) and 2036 (80 percent). Those same patterns would suggest that white voters will make up about 6 in 10 (58 percent) Democratic voters in 2020 and drop to 50 percent by 2036.

Once again, this drop is driven almost entirely by the decline of white noncollege voters. If current demographic trends persist, white noncollege voters should be 42 percent of voters in 2020 and 35 percent of voters by 2036. We expect white noncollege voters to be 58 percent of Republican voters and just over one-quarter (27 percent) of Democratic voters in 2020. Despite their dramatic decline, white noncollege voters will still make up the majority (51 percent) of Republican voters by 2036 but just about 1 in 5 (22 percent) of Democratic voters.

We do not expect the share of white college voters to change dramatically over the next five elections. They should continue to be 30 percent of voters in 2020 and shrink slightly to 29 percent of voters by 2036. Similarly, by 2020 and 2036, the share of Democratic voters (31 percent versus 28 percent) and Republican voters (28 percent versus 29 percent) that are white college graduates will change only slightly. Notably, white college voters will make up the plurality of Democratic voters over this entire 16-year period.

Black voters

In 1980, about 1 in 10 (9 percent) voters were black. The relatively lopsided nature of black support for Democratic candidates created a large compositional gap between the parties. While black voters made up 1 in 5 (20 percent) Democratic voters in 1980, they were just 1 percent of the Republican coalition.

Black voters are, far and away, the most stable coalitional element in our study. Due to relatively low immigration and modest birth rates, black eligible voters have only grown at about the same pace as all voters. As a result, the rough size of this group has not changed significantly over time. Black voters have grown just slightly as a share of all voters (12 percent), Democratic voters (22 percent), and Republican voters (2 percent).

Current demographic trends suggest that this group will only grow marginally going into the future. Absent any shifts in turnout, black voters should make up an identical portion of voters, Democratic voters, and Republican voters in 2020. However, by 2036, black voters will make up 13 percent of all voters, 23 percent of Democratic voters, and 3 percent of Republican voters.

These are small changes relative to 2016, but this stability will result in black voters surpassing white noncollege voters by 2036 as the second largest voting block within the Democratic Party (23 percent versus 22 percent). This would be another milestone event in the demographic evolution of electorate.

Hispanic voters

In 1980, Hispanic voters made up just 3 percent of all voters. While the compositional differences between Democratic (4 percent) and Republican (2 percent) voters were not large in absolute terms, the gap was representative of the divide observed in later elections.

As a result of significant immigration in the intervening years and a younger age distribution, Hispanic voters have grown slowly and steadily as a share of all voters. By 2016, they made up almost 1 in 10 (9 percent) of all voters.

Throughout this 36-year period, Hispanic voters have consistently been a larger share of Democratic voters than Republican voters. While Democratic and Republican voters were about equally Hispanic in 2000 (6 percent versus 5 percent) and 2004 (7 percent versus 5 percent), this compositional gap grew after 2008. By 2016, the size of the Hispanic group within the Democratic Party was twice the size of the group within the Republican Party (12 percent versus 6 percent).

Going forward into the future, the size of the Hispanic population will continue to grow. With the majority of the growth among Hispanics coming from native births rather than immigration, Hispanics will continue to make up a larger and larger share of both eligible voters and voters overall.

By 2020, Hispanic voters will make up a slightly larger share of all voters (10 percent) and Democratic voters (14 percent) and a roughly equal share of Republican voters (6 percent). Even if we assume that this group’s turnout does not increase, Hispanic voters will surpass black voters as the largest nonwhite voting group by 2032. By 2036, Hispanic voters should make up about 14 percent of all voters, almost 2 in 10 (18 percent) Democratic voters, and 1 in 10 (10 percent) Republican voters.

Asian and other race voters

In 1980, just 1 percent of voters were Asians or belonged to another racial group. These voters made up an equal share of Democratic (1 percent) and Republican (1 percent) voters.

Due to rising immigration from Asian countries, Asian Americans have become the fastest growing racial group. As a result, Asian voters and those belonging to other racial groups made up 6 percent of all voters in 2016—including 7 percent of Democratic voters and 4 percent of Republican voters.

Going forward, current demographic trends predict slow but steady growth. By 2020, Asian voters and those belonging to another racial groups will together make up a very similar number of all voters (6 percent), Democratic voters (7 percent), and Republicans voters (5 percent). These figures will rise slightly by 2036 (8 percent, 9 percent, and 7 percent, respectively).

Voters by age

In 1980, just more than half of voters were under the age of 45, including 23 percent who were ages 18 to 29 and 28 percent who were ages 30 to 44. About one-third (32 percent) of voters were ages 45 to 64 and just fewer than 1 in 5 (17 percent) voters were ages 65 and older. At this time, the Republican and Democratic parties were very similar in terms of their age composition, with roughly equal numbers of 18- to 29-year-old voters (22 percent versus 21 percent), 30- to 44-year-old voters (28 percent versus 27 percent), 45- to 64-year-old voters (32 percent versus 33 percent), and voters 65 and older (18 percent versus 18 percent).

Over the next 36 years, two significant changes occurred. First, the number of voters younger than 45 shrank while the number of voters 45 and over grew. Second, the parties’ once similar age compositions grew apart.

By 2016, the number of voters ages 18 to 29 dropped 7 points (16 percent). While the number of young voters among Democratic and Republican voters was relatively similar prior to 2004, that election marked the first significant divide between the parties (19 percent versus 13 percent). By 2016, about 2 in 10 (19 percent) Democratic voters and about 1 in 10 (11 percent) Republican voters were ages 18 to 29.

While the number of 30- to 44-year-old voters was relatively stable between 1980 and 2004, it dropped about 6 points by 2016 (22 percent). While the number of voters ages 30 to 44 among Democratic and Republican voters was relatively similar prior to 2000, there was a larger difference that year (28 percent versus 33 percent). This Republican advantage held in 2004 (25 percent versus 30 percent) but flipped in 2008 (26 percent versus 23 percent) and then expanded in 2012 (26 percent versus 20 percent). By 2016, 30- to 44-year-old voters made up one-quarter (25 percent) of Democratic voters but just fewer than 1 in 5 (19 percent) Republican voters.

(The solid lines are observed figures for the composition of the overall voting electorate, of Republican presidential voters, and of Democratic presidential voters through 2016; the dotted lines are projections through 2036 using our baseline model.)

While the number of 45- to 64-year-old voters was relatively stable between 1980 and 1992, this group grew in size afterward—peaking in size in 2012 when 4 in 10 (39 percent) voters fell into this age range. In 2016, the percentage of voters in this group dropped slightly (37 percent), but still represented the largest age group in the electorate. While 45- to 64-year-old voters made up roughly equal shares of Democratic and Republican voters between 1980 and 2004, the parties began to separate in 2008 (37 percent versus 40 percent). By 2016, 45- to 64-year-old voters made up more than 4 in 10 (41 percent) Republican voters but just 35 percent of Democratic voters.

By 2016, the share of voters 65 and older grew by 7 points (24 percent). While the number of seniors in the party coalitions was relatively similar prior to 2008, they made up a notably larger share of Republican voters that year (22 percent versus 17 percent). By 2016, the gap between the Republicans and Democrats had grown even larger (30 percent versus 21 percent).

Overall, the 36-year period between 1980 and 2016 saw those younger than 45 shrink as a share of the electorate and begin to make up a larger share of Democratic voters. Consequently, those 45 and older made up a larger share of voters and became a disproportionate percentage of Republican voters.

By 2020 and 2036, the number of 18- to 29-year-old voters will shrink slightly (15 percent and 14 percent, respectively); 30- to 44-year-old voters will remain stable (23 percent and 23 percent, respectively); 45- to 64-year-old voters will shrink (35 percent and 32 percent, respectively); and those 65 and older will grow (26 percent and 32 percent, respectively). Notably, while 45- to 64-year-old voters will have constituted the plurality of voters between 1980 and 2032, growth among voters age 65 and older will finally make these two groups the same size in 2036.

The compositional differences between the parties will remain roughly proportional during this time period. While 18- to 29-year-old voters will make up fewer than 1 in 5 Democratic voters in 2020 and 2036 (19 percent and 17 percent), they will be just about 1 in 10 Republican voters (11 percent versus 9 percent). Similarly, 30- to 44-year-old voters will make up about one-quarter of Democrats in these two elections (26 percent and 25 percent) and just fewer than 2 in 10 Republican voters (19 percent and 19 percent).

By contrast, older Americans will continue to make up a disproportionate share of Republicans voters. While 45- to 64-year-old voters will make up almost 4 in 10 (39 percent) Republican voters in 2020 and more than one-third (34 percent) in 2036, they will be just 33 percent and 30 percent of Democratic voters in those same years.

Voters age 65 and older will continue to make up a disproportionate share of Republican voters but grow as a share of both parties. By 2020, they will make up about one-third (32 percent) of Republican voters. Astoundingly, seniors (36 percent) will overtake 45- to 64-year-old voters (34 percent) and become the plurality of the Republican coalition by 2028. By 2036, they will constitute 38 percent of the Republican voting coalition. Among Democratic voters, those age 65 and older will make up almost one-quarter of the coalition by 2020 (23 percent) and nearly 3 in 10 (28 percent) by 2036.

As noted earlier, we examined projected changes in party composition not just using our baseline model but also with significant changes in turnout and party support rates among different groups. What these data show is that, while shifting turnout and support rates can be pivotal for winning elections, these changes should have a relatively small impact on the overall makeup of the electorate and the parties’ coalitions. This indicates that most of the effect of demographic change on future party coalitions is already baked in and will reshape party coalitions—in a sense, whether these parties like it or not.

Equalized turnout across racial groups

In the modern political era, the turnout rates of blacks, Hispanics, Asians, and those belonging to other racial groups has typically lagged behind that of whites. What would the electorate and the parties look like if those gaps were closed?

In order to determine this, we set the turnout rates of various subgroups equal to the highest turnout observed across racial groups. So, for examp