Continued from page 1

Conservative pundits said the speech may have backfired, with Mr. Romney’s defense of the individual mandate serving chiefly to bolster Mr. Obama’s plan.

Mr. Gingrich has had to apologize profusely for his criticism of House Republicans’ plans to overhaul Medicare. He has gone so far as to say that his words shouldn’t be used in attack ads against the GOP. Undeterred by the warning, Democrats have gleefully repeated the former speaker’s attacks.

Mr. Pawlenty has employed a “nobody is perfect” defense of his previous stance on cap-and-trade, telling audiences and interviewers that everybody running or considering a bid for president has “a few clunkers” on their records, and that his are fewer and less severe than most.

“If anybody is perfect, come on up here and stand by this podium, because we’d like that person to be running for president,” Mr. Pawlenty said at the first presidential debate in South Carolina.

Chris Chocola, president of the Club for Growth, said that “the term of the campaign may be ‘clunkers.’ “

“They all have clunkers,” the former congressman from Indiana said. “I guess the question is whether they own up to them or not, and whether they learn from them or not.”