I think the answer to that is apparently in the behavior of the GOP - they clearly believe that if they ever lose power they'll never get it back, and are prepared to break the system to prevent it. Their best bet is to burn the country to the ground and take possession of the ashes. Also on the plus side, they finally started radicalizing the left, something we haven't seen since the '60s. More division = good.
The chaos and cruelty isn't incompetence, it's strategy.
The hope is to hold it together long enough for White Evangelicals and other assorted members of The Former Guy's base to lose relevance, forcing the GOP to appeal more to the center.
Looking back in history, though, I'm not hopeful. The American right has been a horrorshow since the '50s: McCarthy, Nixon, Gingrich, GW Bush, TFG; racism, sexism, religious bigotry; intolerance and censorship...
The problem is, you talk about common ground as if the right wants that, when in fact that would be the end of them. They very proudly won't compromise, and say so. I'm unclear why people keep pretending or not realizing that - they aren't keeping it a secret. The Democrats can't play that way : the GOP is 75% White Christians, the Dems are like the effing U.N. Everything they do has to be a compromise among the various factions on the left, the right is pretty monolithic.
Also on a similar track, all this talk about "we" and "us" is alien on the right. Look at their philosophy - they don't believe in the notion of "us" as a nation. Again, this isn't my being too rigidly ideological or a conspiracy theory, they come right out and say it. They don't want a federal government at all, it's "collective" action, and they don't believe in it.
Is the left perfect? No, they're a bunch of fuckups, because they're people. But at least the possibility of compromise exists. Until the right changes, we're hosed.