Not having to worry about re election may be a very liberating thing for the Chairman of the House Oversight Committee
There was a story, perhaps apocryphal, in early 1963, long before he was assassinated, that then President Kennedy called Barry Goldwater into the Oval Office, and said, “Barry, you want this G*d-damned job? Take it!”
Being the bearer of a lonely and thankless task which seems to have no chance of resolution can wear away anybody’s enthusiasm. Some more quickly than others.