Connecticut voters have a more favorable view of Rep. Christopher Murphy (D) than of his Democratic rival in the Nutmeg State’s 2012 Senate contest.

Murphy’s apparent advantage was outlined in polling released Tuesday by the Yankee Institute for Public Policy, a think tank based in Hartford, Conn, that hired Pulse Opinion Research to survey 500 likely Connecticut voters on June 9.

Forty-eight percent of likely voters had a favorable view of Murphy, who launched his Senate candidacy shortly after Sen. Joe Lieberman (I) announced his plans to retire at the end of his current term. Another 22 percent have an unfavorable view of the three-term Congressman, and 30 percent said only that they’ve heard of Murphy or aren’t sure.

Murphy’s Democratic rival, former Secretary of State Susan Bysiewicz, won favorable marks from just 34 percent of likely voters and unfavorable ratings from 43 percent; 22 percent of respondents said only that they have heard of her or aren’t sure.

The Yankee Institute did not test a head-to-head matchup of the Democrats.

Bysiewicz’ relatively high unfavorables could be related to problems in the 2010 election cycle. She first launched a gubernatorial bid, then shifted to the attorney general’s race, only to have the state Supreme Court rule she was unqualified for the post.

On the Republican side, while the field has yet to take shape, 2010 Senate candidate and former World Wrestling Entertainment CEO Linda McMahon nearly matched Murphy’s favorables with 47 percent positive ratings. But 48 percent of likely voters have an unfavorable view of the Republican, who spent $50 million on an unsuccessful Senate campaign last fall and is expected to announce her 2012 intentions in the coming weeks.

2010 GOP gubernatorial candidate Tom Foley, also part of the Senate discussion, earned favorable marks from 41 percent of respondents and unfavorable marks from 37 percent.