Manfred changed the rules for Pete Rose specifically because Trump wanted him to. He was never going to change eligibility rules for Rose otherwise.

But Clemens is already eligible for the Hall, whereas Rose was banned. Manfred can’t guarantee either will be elected.

No, and as Trump's post says today, Trump is mad that he won't do more for Rose, despite the fact that making him eligible was a HUGE deal that wouldn't have otherwise happened. Which goes back to my initial point: Manfred has to tell Trump no. Which he never has done before.