Well, I am no expert, but it seems to me that Mueller is more comfortable and candid with the republicans.
He is generally on high alert with the dems and their questions until he hits the "safe" questions he has a prescribed answer for.
What shocks me is how I need a shower after listening to the democrats. Good God those are some practiced smiles and lispy words. Well - and how they seem to think this plan of theirs is going to work.