From Robert D. Novak:
Sen. Joseph Lieberman's friends are certain that if Democrats expand their one-vote Senate edge in this year's elections, they will kick him out of the Senate Democratic caucus and, therefore, oust him as Homeland Security Committee chairman.
Lieberman risked the usual punishment of ejection from the party caucus when he endorsed Republican Sen. John McCain for president and actively campaigned for him. But with Democrats in a Senate majority of only 51 to 49, they would lose control if Lieberman defected to the Republicans.
After being defeated by an anti-Iraq war candidate in the 2006 Connecticut Democratic primary, Lieberman kept his Senate seat in the general election by running as an independent and now calls himself an "Independent Democrat." He became Homeland Security chairman under the Democrats' strict seniority rules by remaining in the party caucus.