The notion that a post-Trump era helps Republicans makes no sense.
Any Republican candidate is going to be viciously attacked by the mass media, leftist Big Tech, Hollywood etc.
It does not matter who they are.
At this point the left is in steamroller mode.
They do not care who they run over.
If Trump loses the GOP will disintegrate.
Any rump party remaining will simply be an appendage to the Congressional Democrats.
JD Vance, Tulsi Gabbard, RDS and maybe RFK jr will have to get something new off the ground. The GOP has no central organizing principle which can command a national majority now or in the forseeable future.