What I missed

It wasn’t the Jews, the Blacks, or even the Single Women that won it for him this time.    A lower percentage of Jews and Single Women voted for him than in 2008.  The Black vote was already maxed out.  What made the difference was the increasingly powerful, increasingly Democrat-leaning Hispanic vote.  First, look at what happened in 2008:

Hispanics voted for Democrats Barack Obama and Joe Biden over
Republicans John McCain and Sarah Palin by a margin of more than
two-to-one in the 2008 presidential election, 67% versus 31%, according
to an analysis by the Pew Hispanic Center of exit polls from Edison
Media Research as published by CNN.  The Center’s analysis
also finds that 9% of the electorate was Latino, as indicated by the
national exit poll. This is higher, by one percentage point, than the
share in the 2004 national exit poll.

There were 129,391,711 votes cast for Obama and McCain in 2008, of which about 11,645,254 were Hispanic.  Obama received 7,802,320 of them.  We don’t know yet how many total votes were cast in the 2012 election, but the Hispanic vote is reported to have not only grown, but to have gone more heavily for Obama than before;  I’ve seen reports indicating between 72 and 75 percent voted Democrat.

The numbers aren’t firm yet, of course, because the final totals haven’t been reported.  But even if we assume only another one point percentage increase so that 12.9 million of the approximately 24 million Hispanics eligible voted, the reported increase from 67 to 73 percent would be an increase from 7,802,320 to 9,417,000, which is a substantial portion of Obama’s reported margin of victory.  And those votes are spread out very liberally through swing states such as Virginia, Colorado, and even Iowa.

Before the election, I noted that the big difference between Nate Silver’s take and mine was that I simply did not believe the D+11 and D+7 weights in the state polls.  The reason those differences were justified was that in 2012, Hispanics apparently went from being heavily pro-Democrat to being even more pro-Democrat than the historically second-most reliable group of Democratic voters, the Jews.  That’s the key factor I missed; while I anticipated an increase in the size of the Hispanic vote as more immigrants became eligible over the course of time, I thought it was going to drop in line with the other demographic groups, not vote an even stronger pro-Democratic bias.  Had it fallen 9 points like the Jewish vote, to 58 percent, Romney would have been much more competitive.

This development is particularly troubling for future Republican prospects since even more of the 50 million Hispanics now in the USA will become eligible to vote in 2016.  My previous characterization of Mitt Romney as the last viable Republican presidential candidate may be more significant than I imagined.  This demographic shift indicates that no candidate can expect to run on a Constitutional platform ever again, and appears to seal the irrelevance of the document that George W. Bush once dismissed as a worthless piece of paper.