The Republican playbook is just a thin as people imagine. They, like tRump that they admire, can't legitimately argue that they aren't corrupt, so all they can fall back on is that corruption is so common that it must not matter -- 'elect us anyway'.

From the link:

All Republicans can do, then, is undermine confidence in our systems of justice as much as possible before then. One way to do that is to impeach, perhaps repeatedly, a Democratic president who is clearly innocent of any crimes. Making the impeachment process a joke through shameless kangaroo trials will exhaust the public, and blunt the impact of the word "impeachment." That way, when Trump gets back to campaigning — and therefore back to committing crimes — even the already insufficient accountability tool of impeachment will be substantially weakened.

That's been Trump's strategy from the beginning. He can't convince people he's not corrupt, so instead, he instills the idea that corruption is endemic and therefore unimportant. The rest of the GOP has learned the lesson well, which is why, if they regain the House in 2022, they will likely start impeachment proceedings early in 2023. It probably won't be over Afghanistan — as that will be thoroughly faded from the headlines by then — but Republicans will make up some other B.S. reason. The point is not simply to accuse Biden of crimes but to make accusing someone of crimes a meaningless gesture altogether.