By 2008, minorities had more than doubled their vote share to 26 percent. College-educated whites had increased their share to 35 percent. The big losers were whites without a college degree, who dropped from 61 percent of all voters to 39 percent — a decline of more than one-third from their level in 1984. That is social change at breakneck speed.
By itself, this evolution in America's social structure goes a long way toward explaining why Democrats have won the popular vote in four of the five presidential contests since 1992 after losing (usually emphatically) five of the six races from 1968 to 1988. Mondale in 1984 carried only 40.6 percent of the popular vote. But if college-educated whites, noncollege whites, and minorities all voted as they did in 1984, but were present in the same proportions they represented in 2008, Mondale would have taken nearly 48 percent of the vote. Conversely, if those three groups voted as they did in 2008, but were present in their 1984 proportions, Obama would have lost convincingly.
Since Reagan's day, Democrats have benefited from not only the growing minority presence but also the shifting composition of the white vote. While noncollege white men and women each substantially declined as a share of voters, and college-educated white men grew only slightly, college-educated white women increased their share by more than half. Those women, most of whom are socially liberal and receptive to activist government, consistently support Democrats more than other whites, and their rise frames the Reaganesque challenge facing Romney.
Most polls this spring show Obama running near the 52 percent he won among those upscale white women in 2008, and also remaining very close to his 80 percent showing among all minorities. If Obama can hold that level of support from those two groups, Romney could amass a national majority only by winning nearly two-thirds of all other whites — the men with college degrees, and the men and women without them. To put that challenge in perspective, Reagan, while winning his historic landslide, carried a combined 66.5 percent of those three groups. To defeat Obama, in other words, Romney may need to equal Reagan.
That comparison underscores how important it is for Republicans to eventually loosen the Democratic hold on minority voters (and, to a lesser extent, upscale white women): It's unrealistic to believe that GOP nominees can routinely match Reagan's historic performance with all other whites. But all evidence suggests that it's not beyond Romney's reach this year. Even nearing Reagan's level would be enough for Romney if Obama slips slightly with minorities or well-educated white women and lowers the bar that the GOP must clear with the remaining whites.
In 2010, House Republicans fell just short of winning a combined two-thirds of the vote from working-class whites and college-educated white men. Polls this year show Obama attracting only about one-third of noncollege whites, as few as Mondale. Obama's support among college-educated white men rarely pokes much above 40 percent. And even these numbers could erode further if the economic stall persists. "In terms of the white vote, those numbers have been in dangerous territory for over a year," says veteran Democratic pollster Peter Hart, who advised Mondale. "You can't read the numbers I read and be optimistic."
Among whites, Obama faces a perfect storm: economic discontent, ideological alienation, and, in some instances, racial unease. With more minorities and upscale white women voting, Obama has a much sturdier base than Mondale did. But a Reagan-level stampede to Romney among all other whites would still overrun it.