Why not? He is not being elected President and “eligible to serve” is different than “being elected”. If you are curious about the distinction, there is a post on it here.
How would that work? Is Trump going to arrest all 50 Secretaries of State? Burn down polling places or have ICE deport anyone trying to vote? Give us the details of how they will be cancelled.
Nope. The first time a bill he signs and not the Speaker of the House elected on 3 January 2029, the moment it is enforced there will be a lawsuit. By what logic will the courts ignore the 20th Amendment?