Going to repost my theory: basically Trump's goal was to get a real senate majority while removing Corker+Flake, while at the same time forfeiting the house to the dems. Trey Gowdy and Bob Goodlatte purposely resigned the house judiciary and oversight so that the democrats would get in charge.
Why? I'm not exactly sure, but there would be a serious conflict if they are in charge in investigations that they personally are implicated in. Such as FISA, or AWAN.