Religious fundamentalism.
Unlike like most areas in the Northeast and Midwest, Evangelical church membership is higher than "Mainline" church attendance in the Southeast.
I wouldn't say that's the main cause although it is one of many. I mean states like Idaho, Alaska, and Montana are pretty conservative overall, but they have some of the lowest church attendance/importance of religion in daily life rates in the country.
Likewise states in the Northeast like MA and RI have large numbers of Catholic voters, but are still solidly Democratic.
The kind of conservatism found in the Intermountain West is awfully different that that found in the Southeast. The “conservatism” found in the West is much more libertarian and tends to have much less emphasis on social issues. In Idaho, Montana, and Wyoming the general attitude towards the federal government is “STAY AWAY”!
The South, on the other hand, is arguably one of the least libertarian regions in the entire nation. People living in the South tend to be more receptive of the idea of the welfare state and put most of their conservative emphasis on social issues. In the South people like a government, but only a government that stands up for the “Christian values” on which this nation was “founded”.
As for Catholics in the Industrial Midwest and Northeast, the experience of Catholic immigrants in the United States has been completely different form that of their WASP counterparts. This explains the differences in voting behavior. Also, many Americans are CINO’s (Catholic in Name Only) and, to some degree, Catholicism is nothing more than a token religion.
