The political polarization of religious and non-religious people in America

[Snowstalker Mk. II]

Evangelical blacks are by far the most Democratic voter group.

[Snowstalker Mk. II]

I think the reason that there's a strong religious left with blacks and Latinos and not with white evangelicals is the social message of the church. Black Protestant churches tend to be focused on social justice and civil rights; they're generally pro-life and divided on same-sex marriage, but are solidly in step (or to the left of) with the Democratic Party. A similar case exists with Latinos Catholics (and is why white Catholics are still much more Democratic than white Protestants, even if both voted for Romney).

Meanwhile, white evangelical churches, despite some social justice elements, are more focused on individual salvation; hence, why they vote heavily for a party with Social Darwinist views.

[Snowstalker Mk. II]

(and is why white Catholics are still much more Democratic than white Protestants, even if both voted for Romney).

A large part of this is explained by the large numbers of people who identify as Catholic but never go to mass. White church going Catholics vote GOP about as much as their White Protestant counterparts.

Maybe mainline Protestants, but certainly not as Republican as evangelical Protestants.