From NBC's Andrea Mitchell
Sources inside the Democratic House Caucus say the vote against outgoing Energy and Commerce Committee Chairman Rep. John Dingell turned partly along generational lines - with young turks lining up against the old - and partly because of Dingell's record on environmental issues.
On a human level, many of the Democrat's colleagues are sad to see Dingell's defeat come shortly before the Michigan representative celebrates the 53rd anniverary of his arrival on the Hill. In February, he will become the longest-serving House member ever in U.S. history.
There was a last minute attempt to forge a compromise, which would have had Dingell announce that it would be his last term as Chairman. But neither Dingell or challenger Henry Waxman would go for half measures.
Waxman's victory in the contest for the Committee's gavel could set up a leadership fight for the California lawmaker's subcommittee chairmanship - with some more aggressive members wanting to challenge the next ranking member - Rep. Edolphus Towns of Brooklyn.