In light of factors related to Sen. Joe Lieberman’s expected retirement, Roll Call Politics has moved Connecticut’s Senate race from Tossup to Leans Democratic.

Lieberman, an Independent who caucuses with Democrats, was facing a difficult re-election bid in 2012 that would have likely included significant challenges from the right and left.

Lieberman’s expected absence, however, sets up the likelihood of a traditional two-way race in a state where Democrats enjoy a tremendous voter registration advantage and where President Barack Obama’s place atop the ballot should give the Democratic candidate an additional push. The president registered a 52 percent job approval rating among likely Connecticut voters at the end of October.

A strong field is already starting to take shape on the left. Former Secretary of State Susan Bysiewicz (D) declared her candidacy Tuesday, and Rep. Christopher Murphy (D) is widely expected to follow suit in the coming weeks. Edward Kennedy Jr., an attorney and son of the late Massachusetts Senator, is also thought to be considering a run.

There are strong Republicans in the mix as well, although two of their best potential candidates — the independently wealthy former professional wrestling CEO Linda McMahon and the narrowly defeated gubernatorial candidate Tom Foley — failed to win statewide election in favorable conditions in 2010. And with a relatively popular president atop the ticket, Republicans’ hopes for this seat in 2012 should only diminish.

McMahon lost to now-Sen. Richard Blumenthal, 43-55.

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