Perhaps they realize that now they've set up in Crazytown, Turmpistan, they can't very well hope to pull anti-abortion Democrats over to their side. Those would need a moderate Republican to flock to, and those don't really exist. There are the Trumpists, then a small number of those who criticize Trump. Are any of them a Republican version of Manchin?
I'd be worried and pissed about this if I was a Republican. In that alternate universe, there I was pretending I wanted to ban abortion so that I can suck up votes from people my policies actively hurt, and then along comes the unthinkable: a decision actually giving it to them. Abortion banned, I've now angered pro-choice people on the right, I can't suck up anti-abortion Democrat votes because my party is Trumpified, AND I don't have my wedge issue because SCOTUS settled it; the most I could now do is gripe about future Democrat efforts to establish a statutory right to abort.
Of course it's not all that much better to be a pro-choice person in this universe because it is, of course, a draft that would toss the right entirely. But I can see why Republican politicians might not be too happy about it. (They'll say they are, but in their hearts ...heh)