I don't think "making lying in America acceptable" is the right way to phrase it.
What the Republicans (with Mr. Trump at their head) are doing is legitimizing and empowering the fraction of Americans who reject the Enlightenment idea of objective truth.
You can show a Trump supporter a video of Trump baltantly lying or saying something racist, and they'll insist that he isn't saying the thing he's literally saying in the video. It's utterly terrifying and unlike anything I've seen in American politics in my lifetime.
For example, Kevin McCarthy saying, "You watch what the president said -- he's not saying China should investigate"
https://twitter.com/atrupar/status/1181184452900409345For the record, here is Mr. Trump saying China should start an investigation into the Bidens:
https://www.youtube.com/watch?v=h1Q67tAUiMg