There is NO REASON for Trump to have given McCarthy such a resounding endorsement, including for Speaker, unless McCarthy is blackmailing Trump with his Jan 6 testimony.
If that is the case, Trump will be a massive failure in a second term and should step aside for the good of the nation.
If that is not the case, then Trump is stupid and repeating the mistakes of the past.
Art of the Deal does not mean empowering your enemies unnecessarily.
Pure conjecture.