Trump is now the Republican Party. He defines it and has virtually no opposition. Even the primary candidates mostly ran on the idea that Trump should win.
However, he also has no successor. When he dies, there’s going to be a scramble to figure out who can be the Trumpyest. There’s not going to be an orderly handover of power. I think it’s going to fracture their voter base between traditional conservatives, who will back someone like Ted Cruz, and the batshit crazy ones, who will back a Don Jr type.
Trump, for want of a better term, has the charisma that the entire party is hanging off of right now. Republicans have handed the fate of their party over to this man, because they have no real policies to sell to voters, and Trump voters don’t care about policy. Once he’s gone, there’s no one waiting in the wings to take over.
There’sno similar phenomenon on the Democratic side. There’s a handful of candidates from 2020 that I could see running again, including Kamala Harris and Pete Buttigieg, as well as newer candidates like Newsom. There might be an attempt to make Harris the heir apparent, but there’s no ride or die candidate the way the gop is with Trump.