Trump didn’t simply tarnish the GOP brand in certain circles — that’s a very temporary thing, and Republicans of all stripes had done plenty to tarnish the brand on their own. Trump habituated Republicans and conservatives into conspiracy-theorizing, into lib-owning as the highest undertaking, and into defending corruption and abuse of power.
Yet Trump brought about the end of Roe. That is something every prior Republican decidedly couldn’t do or refused to do…
One relevant question is whether a different Republican nominee would have yielded as good results, Supreme Court-wise, in 2016 through 2020 as Trump did. First, would Marco Rubio, Jeb Bush, John Kasich, or Ted Cruz have beaten Hillary? Maybe anybody with a pulse would have defeated that obviously corrupt, thoroughly unlikable, entirely opportunistic politician. Then again, maybe it took Trump’s unique appeal to the working-class voter in order to carry Michigan, Pennsylvania, and Wisconsin in 2016.
Also, once in office, perhaps it took Trump’s unique disdain for the liberal media to place three conservatives on the high court. When the Washington Post and Democratic senators rallied relentlessly behind uncorroborated sexual assault allegations against Brett Kavanaugh, would another Republican president have caved? When the media and Democrats decided that it was somehow foul play to replace Justice Ruth Bader Ginsburg a month before the election in 2020, would another Republican have gone along with that argument?