(CNN) – A new poll in the race to fill the Connecticut U.S. Senate seat being vacated by independent Sen. Joe Lieberman shows the party frontrunners increasing their leads since the last survey in March.
Democrat Rep. Chris Murphy has grown his lead from 12 points to 30 over Susan Bysiewicz, the Quinnipiac University poll found, while Republican Linda McMahon is now ahead of former Rep. Chris Shays by 29 points. She had a nine point advantage over Shays in the previous Quinnipiac survey, released March 22.
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The Connecticut primary is to be held August 14th.
Should those frontrunners face each other in the November election, Murphy has a three point advantage over McMahon, a former wrestling executive who sought to unseat Lieberman in 2010. That margin is within the poll's sampling error of plus or minus 2.6 percentage points.
Other possible matchups involving combinations of McMahon, Murphy, former Secretary of State Bysiewicz, and Shays show similarly tight races, with margins of eight points or less.
President Barack Obama has a 12-point lead over GOP presidential candidate Mitt Romney, 50% to 38%. The CNN Electoral Map rates the state as safe in Obama's column.
Lieberman, an independent who was formerly a Democrat, maintained a 50% favorability rating in the poll.
This Quinnipiac University survey included 1,408 likely Connecticut voters between May 29 and June 3.