The Changing Demographics of Party Affiliation

Wall Street Journal:

The Republican Party has grown more conservative, more downscale economically, older and more Southern in character. In that light, its revolt against what is perceived as a Wall Street-led establishment and the polite, small-c conservatism that was personified by Gerald Ford is only natural.
The Democratic Party has grown more liberal, younger, more urban and demographically diverse, with a bigger overlay of upscale activists from the two coasts. The moderate-to-conservative Democrats in Southern states who helped put Bill Clinton in the White House then aren’t available for Hillary Clinton now. Seen through that lens, the picture of college students streaming to hear Bernie Sanders makes more sense....
For starters, the two parties have become more ideological and more ideologically divided at the base. In a large survey of voters done in mid-1990, the Journal/NBC News poll found that just 12% of Republicans identified themselves as very conservative, and only 13% of Democrats identified themselves as very liberal. Today, those shares have roughly doubled. In the latest Journal/NBC News poll, taken last month, 28% of Republicans called themselves very conservative, and 26% of Democrats called themselves very liberal.
 The share of blue-collar workers identifying themselves as Republicans has risen to 44% from 35%. Meanwhile, a somewhat higher share of Americans in the top income levels are likely to be Democrats than was the case 25 years ago.
And, amazing as it may seem now, a quarter century ago, those age 18 to 34 were more likely to identify themselves as Republicans than as Democrats; meanwhile, those age 65 and over were more likely to call themselves Democrats than Republicans. Today, the youngest Americans are far more likely to call themselves Democrats than Republicans, and the oldest Americans are as likely to call themselves Republicans as Democrats.

I think the part about how 25 years ago younger people were Republican and older people were Democrats is easily explained by the fact that the older people came of age in the New Deal era, while the young people came of age during the Reagan era.  Nowadays, the young people came of age during the Bush II debacle, while the older folks were in the prime of their life during the Reagan era.  Anyway, I still don't understand how the Republican party contains so many blue collar workers even though the party's policies punish them, while the Democratic party has attracted more rich folks, even though they are likely to fare more poorly under Democratic policies.