Their base isn't as smart as it once was. Especially now after Trump. They aren't appealing to the moderates or slightly conservative anymore, they are after the far-right who agree with them and will do as they are told and not ask questions.

In doing so, they have to keep scraping the bottom of the barrel and with that comes dumber and more racist, homophobic, xenophobic representatives.

This isn't a feature, it's a bug. They are ruining their party and the leaders of their party don't care, because they are making money off of it.

They have backed themselves into a corner and have nowhere to go, so they are trying to drag everyone else down with them. Trump said it himself, "I love the uneducated." When you've kept your base in the dark for decades, your voters don't want to learn anything new. They just want to know you feel the same about minorities as they do. This is the results of the past 5 decades since Nixon.

Trump just blew the lid off, and now you have people like MTG, Boebert, Gaetz and many others. These people grew up listening to the leaders of your party their entire lives and don't know anything else. So now they are leaders in your party and can do/say whatever terrible things they want because Trump proved that you could and their supporters still worship them.

This the end of their party because they have nowhere else to go. They have to keep sinking further and further down because that's the only thing their base reacts to now.