The Democrats' shift produced vote gains in some segments of the electorate. Blacks, who voted 62 percent for John Kennedy, have voted about 90 percent Democratic starting in 1964.
Democrats' dovishness and liberal stands on cultural issues won them support from the growing percentage of college-educated voters. But those same stands cost them support among those who came to be called "Reagan Democrats."
Talented Democratic strategists like pollster Stanley Greenberg and elections analyst Ruy Teixeira struggled for decades to come up with strategies to bring the white working class back to what they considered their natural political home. But even Bill Clinton was unable to get them back.
You can see the results in the 2008 exit poll. Barack Obama got a higher percentage of the total vote than any other Democratic nominee in history except Andrew Jackson, Franklin Roosevelt and Lyndon Johnson.
But he did it without capturing the vast middle of the electorate. He won with a top-and-bottom coalition, carrying voters with incomes over $200,000 and under $50,000, and losing those in between. He carried voters with graduate-school degrees and those with no high school diplomas, and ran only even with the others.
Obama lost among noncollege whites by a 58 percent to 40 percent margin. And in the 2010 House elections, non-college whites went Republican by 63 percent to 33 percent.
So maybe it makes sense for Obama to write off the white working class. Yet he is doing it in an odd way, by enacting New Deal-like programs and expending great energy on raising taxes on high earners.
Historically, that was the way to win working class votes. But it plainly isn't doing so now, and it seems poorly calculated to enthuse the top half of the top-and-bottom coalition. Class warfare is a dubious strategy when you've written off the working class.