Speaking as someone who grew up in Texas in conservative evangelical family, there are plenty of churches that are politically active (not all but there are a lot). So you basically have a voting block that takes marching orders from their spiritual leaders.

I attended such a church until my early 20's (I'm 32 now) and around elections there were many sermon reminders that they needed to go vote for people aligned with their conservative values. At my former church they wouldn't explicitly endorse candidates, but it was understood you voted Republican. If the Republican at least appeared to be an evangelical Christian, you would get more support. (I remember George W. Bush being called a "man of God" by several people.)

Moreover, if you had an inclination to, say, vote Democrat, then you better be quite about it. People would just about question how "true" of a Christian you were if you did that.

Disclaimer: I know that not every church in states like Texas are like this. I know because I went to less political churches too. (I don't go to church anymore for what it's worth.)