Lieberman had threatened to defect to the Republican Party if Democrats pulled him from his perch atop the powerful Homeland Security and Government Affairs Committee. (Instead they agreed to remove him from a lesser chairmanship, that of a subcommittee beneath the Environment and Public Works Committee.)

The compromise, though, didn’t satisfy Sanders. From Politico:

Bernie Sanders (I-Vt.) — one of 13 caucus members who voted against the deal — challenged Lieberman over his threat to leave the party if he lost control of the Homeland Security panel. “If you are a Democrat in your heart, why do you need your chairmanship to remain one?” Sanders asked Lieberman, according to a senator who attended the closed-door session.

No word on Lieberman’s response.

Sen. Tom Carper (D-Del.), a close ally of Sen. Joe Lieberman, said the Connecticut Independent should pay a price for his campaign attacks against President-elect Barack Obama.

“There need to be consequences, and they cannot be insignificant,” Carper said in a Monday interview with The Hill.

Lieberman, who campaigned actively for GOP presidential hopeful John McCain in recent months, is set to make an appeal to Democratic colleagues tomorrow over his standing within the caucus. Afterwards, members will hold a secret vote to decide what repercussions, if any, the Homeland Security chairman should face.

After picking up at least six Senate seats this month, Democratic leaders next year won’t have to play the same game of catering to Lieberman out of fear that he would desert the party, thereby eliminating their slim majority in the upper chamber. Still, he’d be an important ally as Democrats try to overcome the GOP filibuster machine that killed so many Democratic bills over the past two years. That dynamic, along with Obama’s call for bipartisan comity, might leave Lieberman with just a slap on the wrist.

“I’m very disappointed as a friend and a colleague,” Carper told The Hill Monday

It remains to be seen whether disappointment will translate into ramification.