I read a comment on reddit saying if the Republicans have genuine concern the Democrats will control both houses of Congress and the Presidency, which from what I have read, they do. They could leverage the threat of increasing the court's size and tilting it back their way by one if they put someone in.
The thought that they will wait till after the election at least makes sense. I doubt they would ever abolish abortion thinking on this situation and its implications. It's such a juicy red meat issue for the religious ideologues, they couldn't find a better one. Better to always be dangling that carrot, rather than ever let those voters catch it. They literally have to do nothing else for those voters, fuck them over, tax cuts for the uber rich etc. So long as they pretend to care about the 'unborn' they are golden.