I agree that the decision to retire needs to be strategic, but I think that retiring now would be a bad strategic decision. Any remotely liberal justice would make it extremely difficult to get Manchin and Sinema on board with, especially since they could fall back on "it's too close to the election" as an excuse. And the potential for an open seat could be a motivating factor for conservative voters and donors.

It seems pretty clear that the conservatives on the court aren't crazy enough to blatantly give the election to Trump if Biden clearly wins, so I think the best strategy would be to trust that Biden will still be president this time next year, and for Sotomayor to retire then. Refusing to confirm a justice for six months is very different from refusing to do it for four years, and will be a bad look for conservatives. Either a few of them will fold or it will hurt them in the midterms.

If Trump wins, well, then I have no idea what's going to happen, but I don't think that the differecne between two liberals and three on the supreme court will matter much.