The GOP, RNC, or whoever, know this already, on top of rural covid death rates being especially bad after the 2020 election. Instead of appealing to moderates or de-extremizing or having any policy platform whatsoever (almost: see below) besides cultural warfare, the radicalization continues. The only explanation is that the GOP is banking on unfair elections. And indeed, "legally" engineering such is arguably the most coherent nationwide GOP policy goal. I wish I shared your optimism, but I think the republican party is about to terminate the American experiment rather than change their ways.
The Republican Party is trapped in a Prisoner's Dilemma - they gotta rush to the right faster than the other guy because the most extreme viewpoint gets the most out-of-state dark money. Unfortunately that which wins the primary is rapidly diverging from that which wins the election. 65% of America supports some form of gun control. 75-80% of Americans support some form of legal abortion. 70% of Americans support single-payer healthcare. 70% of Americans support same-sex marriage. 75% of Americans think the country has work to do on gender equality. 64% of Americans want to raise taxes on the rich. The mechanics of American electoral politics have required Republicans to demonstrate their extremism. This has gotten us extremist politics. However, what started as a populist revolt against mainstream Republican positions has now become a tail wagging the dog. I'm not confident in my hypotheses? But I can argue with confidence that the extremist positions in Republican electoral politics do not represent extremism in the electorate.
Not that I've ever followed the space closely, but I've never read a really good game theory based explanation of why they behave the way they do. It seems to be a feature of all one party political divisions that they revert to the extreme, and most of our country is a de facto one party system. It certainly seems to encourage politicians to behave in the "purest" possible way, but at some point, there's no where to go but crazy, where you come up on the fly with an explanation that the shooter is a "transsexual illegal leftist" without regard to facts, because if you don't say it someone else will and then you're the lefty. When you have to protect both flanks, as you should have to in a two party system, there's a tension that pulls in both directions. When all the pull is only to one direction (and of course it happens on the left a lot, too, it's just that it's so much more obvious when it's a minority party who is for the most part also poor, uneducated and racist), the positive feedback will continue until implosion. The only thing that can stop it is a moderating force, which could easily come from more moderate people moving to rural areas. I'm not going to say I'm a fan of Brian Kemp, but his rejection of Trump and his 52 point win give me hope. The cult of personality is cracking, though it's still intact for now. My vision of a moderating force that could help bring rural America back to reality is someone Jimmy Carter-like. I know that sounds weird, since the GOP looks at Carter as the worst president this side of WWII, but he's a mild mannered white Christian who speaks the language (Southern, I mean) and knows how to connect with rural America. They're waiting for a Messiah, and they thought they found it in Trump, but Trump only knows how to piss off libs, not how to actually bring back the jobs.
Allow me to again recommend this book. Here's the important bit: For anthropological, biological reasons, liberals have to be convinced to follow a political party while conservatives have to be convinced not to. Liberals hate the Clintons because they're hypocrites; conservatives are untroubled by hypocrisy. Any liberal argument you've ever witnessed has been some form of "REASONS!" while every conservative argument you've ever witnessed has been some form of "TEAM!" None of this shit is binary, though. There's a spectrum of liberal-to-conservative thought and liberal-to-conservative political affinity but, in the words of Jon Stewart, "American politics is determined by the extremes because the people in the middle have better shit to do." If you're willing to blow a day standing in front of a Planned Parenthood with a poster of an aborted fetus on a stick, I know two things about you: (1) we don't vote the same (2) you feel much stronger about this than I do. Now add the fact that running for Congress costs an average of over a million dollars (for a job with a salary of $174k) and the perversions become clear. And I mean, I'm guilty. Apparently I bought one half of a useless Amy McGrath vote in 2020. If you don't have national attention, you will lose. And for a local politician to earn national attention, you either have to be Marjorie Taylor Greene or be running against Marjorie Taylor Greene. The mechanism that I hope saves us is that the sane will care more than the crazy. That's the only way we ended up with Raphael Warnock.When all the pull is only to one direction (and of course it happens on the left a lot, too)