(Reuters) - Veteran Democratic Congressman Ed Markey has extended his lead over Republican Gabriel Gomez in the race to fill Massachusetts's open seat in the Senate, according to a poll released on Wednesday.
Some 52 percent of registered voters said they supported Markey, compared with 40 percent backing former Navy SEAL Gomez, the New England College poll found. That is a broader lead than earlier polls.
The split largely reflected the state's overwhelmingly Democratic electorate, said Ben Tafoya, who ran the poll.
"The clock is running out for Gomez, but it's not inconceivable that something could happen in the debates to change things," Tafoya said.
The two candidates will face off Wednesday night in the first of three debates leading up to the June 25 special election to fill the seat that became available when President Barack Obama named then-Senator John Kerry as secretary of state.
The seat is one of two at play in the U.S. Senate, where Democrats currently enjoy a majority of 54 seats, including two independents who caucus with the Democrats, to 45 seats held by Republicans.
The death of New Jersey Senator Frank Lautenberg earlier this week leaves one seat open. New Jersey Governor Chris Christie, a Republican, has called an October 16 special election to fill that seat. Christie has said he will pick someone to fill the seat on an interim basis until the special election.
In Massachusetts, Democrat William Cowan is serving as interim senator until that state's special election.
Markey and Gomez have made the national Republican Party an issue in the Massachusetts race, with Markey's campaign trying to tie Gomez to a party that tacks more conservative than many Massachusetts voters, while Gomez has stressed his independence.
Gomez, a private equity executive, told voters in Springfield early this week that if elected, he might be regarded as a "pain in the butt" by many Republican leaders in Washington.
Massachusetts's other sitting senator, Democrat Elizabeth Warren, defeated Scott Brown in November with a campaign strategy focused on tying him to the national Republican leadership.
In the New England College poll, roughly three-quarters of registered voters in each party backed their party's candidate, with Gomez enjoying a slight lead among independents. The poll surveyed 734 voters on June 1 and 2.
For Gomez, the challenge will be to win over independents, Tafoya said.
(Writing by Scott Malone; editing by John Wallace)