Sen. Marco Rubio, R-Fla., one of Romney's most prominent surrogates, said Obama's 1998 remarks give "more insight into what he views government's role as."
"This is a president who believes the government's job is to pick winners and losers in the economy," Rubio told reporters Wednesday.
Sen. Lindsey Graham, R-S.C., suggested that Romney should campaign more aggressively in key swing states, particularly Virginia.
"If we win Virginia and one of Ohio and Florida, we're going to win this thing," Graham said. "So, if I were Mitt Romney, no person in Virginia could go very long without meeting me."
Democrats appeared buoyed on Wednesday. Obama's campaign manager, Jim Messina, met behind closed doors with Senate Democrats for their weekly caucus lunch, a gathering described by participants as upbeat.
Sen. Dick Durbin, D-Ill., said Messina told senators that he expects the presidential race to remain close, but he also described polling data from key swing states that appeared to be solidifying for the president.
"What impressed me, as much as anything, was the pace of volunteers, calls, voter registration is dramatically larger than it was four years ago," Durbin said of the data.
In another sign of renewed Democratic optimism, House Minority Whip Steny Hoyer, D-Md., suggested Wednesday that Romney's dismissal of nearly half of the American electorate could work to swing key House and Senate races.
"I think what's happening is that the American people, particularly the middle class in America, are getting a clearer and clearer picture that the Democratic Party is on their side and the Republican Party is not," Hoyer said.
On the Republican side, that possibility was causing some concern among some GOP candidates, who were direct in seeking to distance themselves from Romney's video comments.
Sen. Dean Heller, locked in a tight race for reelection against Democratic Rep. Shelley Berkley in Nevada, became the third GOP Senate candidate to take issue with Romney's comments, telling reporters Wednesday that he has "very different view of the world" when it comes to competing for the votes of those who do not pay income tax or who receive government assistance.
And Mark Meadows, a Republican running for an open House seat in the Asheville, N.C., area, said that voters in his district don't fit Romney's description at the fundraiser.
"I'm concerned about all 750,000 people," Meadows said at a televised forum Tuesday night. "I am here to represent the people of this district."
Washington Post staff writers Felicia Sonmez and David Nakamura contributed to this report.