Consistent differences have emerged between the kinds of justices conservatives want and the kinds of justices liberals want, but it’s considered out of bounds for politicians to just say “The President has a different ideology from me, he’s appointing a judge whose decisions I anticipate disliking, and that’s one of the reasons I voted for the other guy.” Instead there are these incentives to concoct wild personality defects in the other side’s choices, or accuse them of deliberately subverting the law (”activism”), rather than of simply disagreeing about important issues.
The other aspect to consider is the extent to which the Republican Party is dependent on pro-life activists. It shouldn't be too controversial to note that a substantial portion of the GOP's activist base is primarily abortion-oriented, and these folks believe it so deeply that they will work incredibly hard for free on campaigns. They believe that getting more Republicans elected will mean the end of abortion, but Republican leaders know damn well that doing away with Roe would mean the end of the GOP for at least a generation. So, putting up a public fight over the occasional judicial appointment goes a long way toward maintaining the base's alleigance.
In reality, of course, around 70% of Americans support Roe and that number would necessarily have to include a substantial amount of Republicans, as there are plenty of Democrats and independents who are pro-life. Indeed, I suspect that the base of the GOP is somewhat less hostile to abortion than what one might think from watching Fox News, and that it's country-club types who have the most resistance to Roe, counterintuitively (or maybe not, as Fox News is made up exclusively of country-club types). But in this, as in most issues these days, the GOP is mostly interested in preaching to the choir.
