Things operate differently with groups that are self-conscious minorities. One party may antagonize them in search of votes from other groups. Democrats' efforts to woo blacks and liberal college-educated whites turned off the white working class in the 1980s.
Barack Obama seems to be doing the same thing this year. His support of same-sex marriage won't help with non-college whites. Nor will his blocking the Keystone pipeline with all its blue-collar jobs.
Add to the list the contraception mandate being denounced in Catholic churches. And the move to give work permits to something like 1 million illegal immigrants.
In each case, Obama is trying to instill enthusiasm in a core Democratic constituency -- and poking a finger in the eye of the white working class.
Meanwhile, there is evidence that demographics may not work as strongly for Democrats as many predicted.
The Pew Hispanic Center reported in April there has been more reverse migration to Mexico than Mexican migration into the U.S. since 2007, and the Pew Research Center reported Monday that in 2010 there were more mostly high-skill immigrants from Asian than mostly low-skill immigrants from Latin America.
According to exit polls, Latinos made up 9 percent of the electorate in 2008 and 8 percent in 2010. They voted 67 to 31 percent for Obama in 2008 and 60 to 38 percent Democratic for House candidates in 2010.
Obama's support among them seems to be holding up well, but Latino turnout may be low, as it was in California's primary. The virtual halt in Latin immigration makes it unlikely Latinos will double their share of the electorate soon, if ever.
Meantime, there are four times as many white non-college voters leaning Republican by a similar margin. Demographics can work both ways.
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