According to the first cut of exit-poll analysis by the Pew Research Center, Obama’s support among white Catholics fell to 40 percent — seven points lower than four years ago. …

In a close election, this reaction might have made all the difference. But the election wasn’t particularly close. And the trend among white Catholics was partially offset by Latino Catholics moving in the opposite direction for reasons unrelated to abortion or religious freedom. (Obama gained three points among Hispanic Catholics and took three-quarters of their votes.) In the end, Obama won the total Catholic vote by a small margin.

This result reveals a tension at the heart of the Republican coalition. The portion of the coalition that is pushing away Latino Catholics is making the political work of conservative Catholics far more difficult. …

In the long run, social conservatives will have serious trouble exerting influence unless they are allied with rising ethnic populations, which tend toward conservative social views. But social conservatives are now in a toxic alliance with political forces — the wall-builders and advocates of self-deportation — that are alienating rising ethnic populations.