First off rip RBG
Am I crazy or does this play out more favorable for democrats than republicans? Hear me out.
1. If Trump successfully replaces Ginsburg, republicans get a 6-3 court advantage and the only response democrats/Biden have will be to pack the court which will gives liberals a 7-6 (or more) advantage. It certainly looks like democrats are more fired up about this than the other side (see: 50mil raised since the announcement of her death), and Biden is clearly the favorite to win as of right now (that could change). Even if he were to lose, it's very likely replacing Ginsburg would at least cost republicans the senate.
2. If Trumps fails to replace Ginsburg, Biden likely (again, as of right now) replaces her. 5-4 conservative majority remains, in that scenario. But Biden would then likely have the potential to replace at least 1-2 more judges in his first term.
My point being...if you're a republican fretting over strategy and what to do...wouldn't it make more sense to...replace Thomas than Ginsburg? If Thomas retires right now, you replace an elderly conservative vote on your terms rather than risking Biden replacing him, the vote will be far less controversial, and you avoid a potential landmine/precedent in the future. If Biden wins in this scenario and replaces Ginsburg...the court remains 5-4 and you remove a nightmare scenario (ie, what if Thomas were to die or retire during a Biden presidency). Then you just hope/pray Roberts doesn't die or retire; for those unaware, Roberts is in moderately poor health and suffers from seizures.
One more point...there is no guarantee Trump will even get his way. Murkowski and Collins have come out against replacing Ginsburg before January 20th. It's possible Romney or Alexander will take a similar position in the coming days. Meanwhile, whoever wins the Arizona senate seat will be seated on November 30th, perhaps in time to vote on the Supreme Court nominee. Dems are almost certainly going to win that seat.