Gomez said the law is hurting middle class families and small businesses, including the state’s medical device manufacturers.
Markey praised the 2010 law, which he has called one of the proudest votes of his career.
Gomez told reporters after the debate that his campaign is drawing enthusiasm not just from Republicans but many independents and Democrats as well.
‘‘I think you would see that we have an amazing amount of momentum and surge going on right now,’’ said Gomez. ‘‘Why else would President Obama be coming to Boston next week? Because they’re scared,’’ he added, referring to the Markey campaign.
But Markey, in his post-debate remarks, scoffed at Gomez’s claim of being a new kind of Republican.
‘‘He’s got the oldest, stalest Republican ideas that he’s running on,’’ the Democrat said.
Markey and Gomez are also scheduled to debate in western Massachusetts on June 11 and again in Boston on June 18.
The election to fill the Senate seat left vacant by the resignation of John Kerry is June 25.