president clearly committed a crime, you’re left with arguing the process"
This is 100% the truth. They can't defend the actions or results of the investigation so they attack the process of the investigation. If the Democrats were doing this in full public hearings, they would be complaining about that too saying the Democrats were trying to smear the president with public hearings.
https://www.politico.com/news/2019/10/23/impeachment-republicans-trump-055688