From 1952 through 1980, in fact, no Democratic nominee reached even 40 percent with college-educated whites, except Johnson. During that same period, no Democratic nominee failed to reach 40 percent of the vote with non-college whites, except George McGovern in 1972 and Jimmy Carter in 1980. Over these eight elections, every Democratic nominee except McGovern ran better, usually significantly better, among non-college-educated whites than among their college-educated peers. This was a world in which Democrats were the party of people who worked with their hands, and Republicans represented those who wore suits and worked behind desks.
But the period since 1984 has seen an accelerating reversal of that historic pattern. During his landslide defeat to Ronald Reagan in 1984, Walter Mondale ran slightly better among college-educated than non-college-educated whites. In the next three elections, Michael Dukakis and Bill Clinton ran almost exactly as well with both groups.
Since then, every Democratic presidential nominee has run better with college-educated than working-class whites. From Al Gore in 2000 through Barack Obama in 2012, the share of the vote won by the past four Democratic nominees among college-educated whites has exceeded their performance among non-college-educated whites by four to seven percentage points.
That shift is rooted largely in the growing prominence of non-economic issues in national politics. On questions from abortion and gay marriage, to gun control, to whether immigrants benefit or burden American society, or Trump’s proposal to temporarily ban Muslim entry into the U.S., non-college-educated whites (especially men) consistently take more conservative positions than white-collar whites (especially women). Polls by the Public Religion Research Institute, for instance, have found that whites without a college education are significantly more likely than those with advanced degrees to believe the values of Islam are incompatible with American values. And while nearly three-fourths of college-educated whites say in Pew Research Center polling that the growing number of immigrants strengthens the U.S., nearly half of non-college-educated whites say they threaten traditional American values.
By contrast, these trends have not affected minority voters in the same way—or meaningfully dented the Democrats’ dominance among them. Through the 1990s, African Americans followed the pattern evident among whites in first decades after World War II, with Republicans running slightly better among those with college degrees than those without. But in every election since 2000, the Democratic nominee has won at least 90 percent of both college-educated and non-college-educated African Americans. Hispanics have not established a consistent pattern of class allegiance (perhaps partly because the sample size even in exit polls is relatively smaller). In 1988, 1996, 2000, and 2012, the GOP ran better among college-educated than non-college-educated Hispanics; in 1992 and 2008 it performed better among non-college-educated Hispanics, and in 2004, the groups split about equally. But Democrats have carried a majority of both groups in every election over that period.