Lieberman won reelection to the Senate in 2006 as an independent after losing the Connecticut Democratic primary because of his support for the war. A number of his Senate Democratic colleagues abandoned him to support the Democratic nominee, Ned Lamont.
That election, in some measure, "liberated me to be totally independent," Lieberman said.
He knows his actions have upset many Democrats.
"A lot of them are not happy, I understand that," he said.
The Connecticut Democratic Party has already stopped inviting Lieberman to its events. The state's Democratic Party chairwoman, Nancy DiNardo, said many members were upset about Lieberman's support for McCain. But she has no desire for retribution.
"If we start going after our people because they aren't agreeing with us on various issues, then we become the Republican Party," she said.
Senate Democratic Leader Harry Reid of Nevada said last week that he had talked with Lieberman about his stance.
"But I'm not about to threaten anybody at this stage," he added.
Lieberman said that on most issues, he's been a good ally of Senate Democrats. Democratic leaders tend to agree.
"Joe Lieberman is a dutiful member of our caucus and provides critical votes on a regular basis," said Sen. Richard J. Durbin of Illinois, the Senate's No. 2 Democrat, noting that the main sources of disagreement are Lieberman's support for the war and McCain.
Still, Democratic disappointment is obvious.
"At some level, there is some understanding," said Sen. Claire McCaskill (D-Mo.), apparently a reference to Lieberman's longtime friendship with McCain and Lieberman's and McCain's support for the war. "At another level, it's awkward. And on another level, it's frustrating."
Lieberman said he initially planned to delay any presidential endorsement until the parties chose their nominees. But McCain called him after Thanksgiving and asked for his help.
Lieberman said his wife, Hadassah, kidded him at the time about getting himself into hot water.
"She said at least this won't last long, because McCain's obviously not doing well," he said.
Republicans relish Lieberman's support of McCain. As the first Jewish vice presidential nominee on a major party ticket, Lieberman could help McCain among Jewish voters, who could be pivotal in some swing states, including Florida.
