How “evangelical” are deep southern whites?

[Indy Texas]

It’s important to note there’s not really a political divide between the cultural elite evangelicals and their poorer neighbors.

A divide could form assuming the children of those cultural elites, cease to be Evangelicals. We see signs of that in the Southern suburbs already.

Also it should be noted that the more wealthier and low country whites have always been less interested in religious based politics and more concerned about class and race. This is why the they were first to become Republicans or start becoming Republicans in the mid 20th century, while the more religious, poorer upcountry whites didn't start getting flipped until the 1990's when the culture wars were at their height. This shouldn't be taken to assume that the former group was not religious, they were just less motivated by issues derived from it comparatively speaking.

It’s important to note there’s not really a political divide between the cultural elite evangelicals and their poorer neighbors.

What is a “cultural elite” evangelical?

I assume he's talking about college-educated, often well-off evangelicals, often in suburban areas.  Not really "cultural elites" in the sense of how it is talked about politically, but still a very different group than the downscale, more rural evangelicals.  Both groups typically vote about the same percentage Republican (~80%), so it's easy to miss the divides, but they're still there.

Upper-middle class evangelicals probably became staunchly Republican before more downscale evangelicals did and are also probably more resistant to voting for conservative Democrats (especially in those sorts of elections in 2016 and before).  However, they are also probably slightly more willing to stay home with a really controversial Republican (i.e. Roy Moore in 2017 in Mountain Brook).  They also probably have higher rates of church attendance (within the evangelical communities) because higher income people tend to be more connected with organizations (including the church) in general.

The two groups probably also differ in what issues they prioritize.  The higher-income group is probably more fiscally conservative and possibly more conservative on social issues like abortion and homosexuality (but talking about it slightly differently), while the lower income group is probably more conservative on things like political correctness and possibly immigration.  The higher income group tended to prefer Cruz and Rubio in 2016, while the lower income group preferred Trump.  The other difference is in things like saving oneself of marriage.  Few people (unfortunately) make it to their wedding day with their virginity, but that's probably slightly more common in higher income evangelical groups.  Also, these are the people who are more likely to be totally abstinent from alcohol (though many still do drink), while drinking is an almost universal part of life in more rural communities.

This is all my personal impression; I don't actually know the stats on these things (other than that polling shows no overall education gap in general elections within evangelicals).

TL/DR: Higher-income, suburban, evangelicals in places like Williamson County, Tennessee tend to be more "churchy" in their lifestyles and have more Cruz-ian politics, while lower income evangelicals are more Trump-ian and populist.

I wonder how each of these groups voted in 1928 and 1948.

Higher-income city-dwelling Southern Protestants definitely swung hard toward Hoover in 1928.

Regarding 1948, do you mean did they vote for Dewey? Or whether they voted for Truman or Thurmond?

[Indy Texas]

RE: BRTD's link, my family was Missouri Synod Lutheran before liking our ELCA church in Iowa City better than its Missouri Synod counterpart ... I get arguments could be made for it being "Evangelical," but I have never heard a single Missouri Synod person describe themselves that way, and that probably matters more.  Personally, I think the simple distinction of falling under the umbrella of any of the traditional Mainline denominations (e.g., Lutheran, Methodist, Presbyterian, etc.) means your Mainline.  Period.  It's not like you can't be a theologically conservative Mainliner, after all.

Most people have much more parochial/idiosyncratic reasons for picking a church from one sub-denomination over another (ex. ELCA vs LCMS; PCA vs PCUSA). People can go from a "mainline" congregation to an "evangelical" one for perfectly mundane reasons like "I like the choir better" or "We moved across town and this one is closer."

And local demographics often drive the tone of the church more than national doctrines that largely exist only on paper. The United Methodist Church is a "mainline" denomination but if you go to a Methodist church in Texas, it probably feels more like a Southern Baptist church than a Methodist church that Hillary Clinton would go to in Upstate New York.