Surveys have found little change in the number of Democrats in the adult public. Roughly one in three Americans identify as Democratic today (and about one in four are Republican)—numbers that have been fairly constant since the mid-1990s.[iii]
But the stable size of Democratic Party membership among the public belies large changes in its composition. Over the past 20 years, while the balance of Democrats and Republicans among the public has remained much the same, the Democratic Party’s demographic profile has undergone a remarkable transformation. Today, the party is more racially and ethnically diverse, includes a larger share of college-educated adults, and has more people who self-identify as liberal. It also includes far fewer religious people.
...A record number of Americans are graduating from college. In 2021, the number of Americans 25 and older who hold a bachelor’s degree rose to 38 percent from 30 percent only a decade earlier.[xv]
Today, college-educated Americans are overrepresented in the Democratic Party (Figure 6). Nearly half (48 percent) of Democrats over age 24 have a degree from a four-year college or university, and nearly one in four (23 percent) have a postgraduate degree.[xvi] In 1998, only 23 percent of Democrats had a college or postgraduate degree.[xvii]
The Republican Party has not experienced similar growth among those with a college education. In 2021, fewer than one in three (31 percent) Republicans had a college education, nearly identical to the number (30 percent) who had a degree in 1998.