Gomez plays for centrist voters in second debate

Gomez touted his support for a $10 minimum wage, the Paycheck Fairness Act and same-sex marriage. He told the audience he was "ashamed" that so few Republicans had supported the Manchin-Toomey measure to expand background checks, and also answered a debate question in Spanish.

"I'm a green Republican," he said at one point.

That answer came in response to a question on the Keystone XL pipeline, an issue on which the two candidates split. Markey has been an outspoken opponent of the controversial project which Gomez supports.

On that and other issues, including tax reform, the National Security Agency surveillance programs and job creation, the candidates also established their differences.

On tax reform, Gomez said he'd be open to eliminating the mortgage interest deduction to achieve a grand deficit-reduction bargain, asserting that he wouldn't go into talks "with any preconditions.” Markey though said he would defend the deduction.

“I do have a precondition and my precondition is that the home mortgage interest deduction is not on the table, that people should be able to rely on that promise, that they will be able to afford the home of their dreams,” Markey said.

He also said he’d end tax breaks for corporations, including oil companies, while Gomez emphasized the need to close personal and corporate loopholes.

On the NSA surveillance program, Gomez said leaker Edward Snowden should be charged as a “traitor” if his disclosures turn out to be harmful, while Markey focused more on protections for civil liberties.

Markey said Americans shouldn’t have to sacrifice their rights to find the “guilty needle” in the “innocent haystack.”

The candidates strayed somewhat from the messaging that shaped the previous debate — Markey mentioned his efforts against "Tea Party Republicans," and Gomez characterized Markey as emblematic of Washington's problems, only a few times. 

Gomez began the debate on offense, charging that ads from Markey's campaign that attacked him raised a “fundamental question of character and trust.” Gomez's campaign repeated that charge in a new ad Wednesday morning following the debate.

Gomez has consistently lagged Markey in polls, though he's managed to keep Markey’s lead down to single digits. 

Democrats though are rolling out their biggest names to campaign and raise funds for Markey to avoid an upset similar to the 2010 special when Republican Scott Brown won.

Vice President Biden headlined a fundraiser for Markey on Tuesday night, while President Obama is scheduled to stump in the state for him on Wednesday.

The candidates will face off in a final debate prior to the June 25 special election.