I know I read an article that identified him as a life-long Democrat, but I'm not finding it at the moment. The hyper-partisan CT Democrat Senate contingent of Blumenthal and Murphy both praised Durham in articles that I just looked up, although that doesn't necessarily make him a Democrat. But, he is a life-long civil servant, so those types tend to be people that won't rock the boat politically. I'm sure that is why he was chosen.
Regardless, nothing more will come of this after Jordan holds his hearing next week. The GOP as a whole should be breathing fire right now, but it is the usual, small group that are denouncing this criminality.