Trump endorsing early means its effect is going to be somewhat "baked in" for a May primary. I.e., don't expect a late surge toward Perdue (like Kemp had in 2018), it's going to be a slog to the finish.
The cleavage here is going to be the state/county GOP organization (Kemp) vs Trump surrogates and aligned national media (Perdue.) I'll rate the primary as toss-up/Tilt Kemp to start.
What do you think Trump is going to do if Kemp indeed wins the nomination? Just sit it out, endorse him reluctantly or will he at least somehow call upon his supporters to vote for Abrams? Latter would be extremely hilarious and instantly move it to Lean Democratic.
I still believe Kemp will go down and the general election is at least Tilt Republican.
Trump probably tucks his tail and goes home to lick his wounds, and there's enough of an anti-Biden vote in November for either Perdue or Kemp to win.
Trump has never, and will never go out quietly. If Kemp wins he probably says it's based on voter fraud and dampens GOP turnout, Senate runoffs 2.0
