He's there to be controlled by the left. Sign whatever they put in front of him, not to actually think or decide anything.

Does he know how Washington works? I'm sure he did at some point. His evaporated faculties got him pulled into the black hole that is his party and he's been puppeted ever since. No different than old ladies getting stuffed into crooked homes and tricked into signing away their rights, other than the country is getting pillaged instead.