There have been many articles and books written about this phenomenon and I don't want to get into them here. Suffice to say that some combination of culture war issues, racial resentment and economic decline has pushed these former Democrats into the Republican column over time. But there has been less attention paid to the parallel shift of white college educated voters to the Democratic Party during the same period.
The Atlantic's Ron Brownstein has been calling this the "class inversion" in which the two parties have exchanged the two white voting factions. He describes it this way:
This generation-long resorting has profoundly reshaped the balance of power both between and within the two parties. Combined with the growth in the minority population, the Democrats’ improving position among college-educated whites has allowed them to win the popular vote in five of the past six presidential elections, despite consistently large deficits among the non-college white voters who constituted the bedrock of their coalition from Franklin Roosevelt through Jimmy Carter. Conversely, the Democratic decline among blue-collar whites has been key to the recent Republican dominance in the House of Representatives.
He points out that the primary electorates of the two parties have also undergone the same change which explains why Trump's crude right-wing populism has been successful and why Clinton's multi-cultural, college educated and older voter coalition won her the Democratic nomination. Trump carried 47% of the Republican white working class and only 35% of college-educated voters. Clinton won college-educated whites in 17 of the 26 states with exit polls and lost roughly the same numbers of the white working class. According to Brownstein, with Trump's base of blue-collar white men and Clinton's base of college-educated white women (as well as people of color) these two candidates are uniquely positioned to finally complete this class inversion.
This is a very bad sign for Trump. First, he has not a snowball's chance in hell of capturing more than a handful of minorities to make up for the loss of college-educated whites. His racism, religious intolerance and xenophobia almost guarantee that the Democrats will maintain, and probably expand, on their dominance among this growing group of Americans.
All classes of white voters are shrinking as a percentage of the electorate, but within that demographic the number of college-educated whites, especially college educated women, is expanding. White men without a college degree constituted 28 percent of all voters in 2004 and by 2012 they were just 17%. Meanwhile,college-educated white women were just 11 percent of the vote when Reagan was re-elected in 84 and had grown to 19 percent in 2012. There are more of them than blue-collar white men. Meanwhile, non-college-educated whites have shrunk from 65 percent of the white electorate when Reagan was sworn in to 36 percent in 2012
So as much as the Republicans may have blown their chances with the rapidly growing Hispanic population with their foolish selection of Trump, the loss of these college educated whites could be even more devastating to their future prospects. The party has been losing some of these voters over the years but they have carried a majority in every election since 1952 when they first began tracking the category, even in the 1964 Johnson landslide against Barry Goldwater. Mitt Romney won college-educated whites by 14 points in 2012. If the trend accelerates in this cycle so that Clinton wins a majority, they're unlikely to go back to the GOP. Just as the Reagan Democrats turned into Republicans, so too will these Republicans become Democrats.
The latest Bloomberg poll of college educated voters has some very bad news for the Republicans:
Among all college-educated likely voters, including those with post-graduate degrees, Clinton leads 54 percent to 32 percent, a much bigger margin than President Barack Obama’s 2-point advantage with a group that represented 47 percent of the electorate in 2012. Among voters with just a college degree and no post-graduate degree, another subgroup Romney won in 2012, Clinton is ahead 48 percent to 37 percent.
“It's extremely hard for any presidential candidate to win an election conceding double-digit deficits among segments of the electorate that their party has competed for and won in the past,” said pollster Doug Usher, who led the survey. “This poll indicates that Trump might be doing just that.”