“Persist” is a funny word to use when you’re talking about human history on an evolutionary level, seeing as how we’ve evolved very little from our conception in Africa only a few hundred thousand years ago, practically the blink of an eye on the evolutionary scale. Even if religion has been around from the beginning of our species, it hasn’t really “persisted” very long at all.
As far as religion’s “use” in an evolutionary sense, the only thing that evolution selects for is more babies. If you have more babies than your peers, you’re more evolutionarily “fit,” it’s that simple. You could then say that religions that encourage their members to have more children are useful, but again, that’s only if you think the most important thing in the life of a human is for them to have more babies. Most people would say other things are more important when it comes to human life, which would make evolution useless as a metric to determine the “use” of religion.
And a Republican thing. Did you forget about the even larger group of people who believe in capitalism even more? I agree that the hand-winging “oh, maybe we’ll vote in a better president in a few years, let’s wait things out” crowd is a pain, but the sentiment that “capitalism is the best we’ve got” is championed primarily by people even further to the right than them.