For GOP, Cruz, Haley, Noem, and DeSantis, will be in the mix with others. There were 19 in 2016. Romney and Pence are kryptonite to the base but there will likley be an estab candidate or two. Trump may run if stars align but may not. Pompeo would be uphill but could run if say backed by Trump and breakaway Patriot or Trump Party.
If Kam has ascended then she will be nom. I would think if Biden isn't running again for whatever reason the party may have him step down so Kam can run as President. If Biden steps down after two years and a day Kam could still have 2 additional terms.
Cruz is done IMO. His schtick doesn't work without Trump noise.