They're not even the most extreme, that's why there's no common ground! The most extreme would be the honest to goodness neo-nazis like the ones marching through Charleston a few years ago, several other flavors of white supremacists and "nationalists" like the NatCons and Bugaloo Boys, religious extremists like Pence, their crazier brother the dominionists like Bill Bar, and outright authoritarians (all of the above).
I'm all for finding common ground, but I don't care for the liberals putting in the extra effort anymore, just to have bad faith actors take advantage of it. It's time for the conservatives to "find common ground" by getting their house in order. Get rid of the Nazis, get rid of the supremacists, get rid of the extremists, and undo all the damage that Barry Goldwater predicted the preachers would do.
Most people aren't that one-dimensional, even when they've wrapped themselves up in a one-dimensonal identity. There is nuance and context to how each person arrives at the conclusions they do, even when they'd struggle to explain or remember it.
If you refuse to empathize, you're making things worse.
Do you know Tylenol can cause horrible death where you have all your skin fall off and veins explode? Do you talk about this when you have take that simple medication?
Try to find common ground. See what you can work together on, see what you can agree upon, rather than point to the most stupid and extreme points of the other side and giving up completely or ignoring all their concerns.