@blatham,
I am not sure if you think they are cowardly or not.
In any event, Bolton is soon to be coming out with a book. If he tells what he actually thought, if it was true he thought the whole Ukraine efforts by Trump was a "drug deal" and if McConnell blocks witnesses by pressuring republicans not to vote for witnesses, it could come back to bite him. On the other hand, Bolton might stick true to form and stick up for the prez and say all those other people were lying. It could go a lot of ways.