Massachusetts Sen. John Kerry told The Associated Press on Sunday that Romney's promise to begin to repeal the Affordable Care Act, better known as "Obamacare," on Day One is "an invitation to total gridlock."
Kerry also questioned Romney's record of bipartisanship in Massachusetts, where Kerry served as a senator while Romney was governor. He said he could count on a single hand his interactions with Romney in those years.
"The mythology of his record in Massachusetts is extraordinary," Kerry said.
Democratic Sen. Dick Durbin, of Illinois, also questioned Romney's bipartisan credentials on Sunday. "If Mitt Romney was such an effective bipartisan governor of Massachusetts, why has he refused to campaign there?" he told The Associated Press.
Asked about Democrats' criticism, Romney surrogate Sen. Rob Portman, R-Ohio, said Sunday on CNN that "to have that kind of response from the Democrats in Congress is discouraging, but, look, I think at the end of the day even Harry Reid and even the Democrats who might take that point of view at this point are going to say we've got to solve these problems."
Indeed, Obama, too, offered a cooperative tone while campaigning in New Hampshire on Sunday.
"As long as I'm president I will work with anybody of any party to move this country forward," Obama said. "If you want to break the gridlock in Congress, you'll vote for leaders who feel the same way, whether they are Democrats or Republicans or independents."
At a freezing rally that brought 20,000 supporters to a Pennsylvania farm, Romney jabbed Obama's inability to work with Congress.
"It's not only Republicans he's refused to listen to. It's also independent voices," he said of Obama, without elaborating.
At a Cleveland afternoon event he added: "You hoped President Obama would live up to his promise to bring people together to solve big problems. But he hasn't. And I will."