By Margaret Chadbourn and Steve Holland
MIAMI/SARASOTA, Florida (Reuters) - Taking a more aggressive tack after a series of reversals, Republican presidential challenger Mitt Romney accused U.S. President Barack Obama on Thursday of "surrendering" in his attempt to change Washington.
A comment that Obama made in an interview with the Spanish-language television network Univision in Florida gave Romney an opening to charge that the Democratic president is ineffective.
Obama told Univision his 2010 U.S. healthcare overhaul was a result of Americans exerting pressure on Washington for action because "You can't change Washington from the inside, you can only change Washington from the outside."
An animated Romney quickly pounced on the remark as evidence that Obama cannot break the political gridlock that has seized Washington as lawmakers grapple with massive debt and annual $1 trillion deficits.
"The president today threw in the white flag of surrender again. He said he can't change Washington from the inside, he can only change it from outside. Well, we're going to give him that chance in November. He's going outside," he said at a rally in Sarasota, Florida.
Romney is struggling to right the ship after damage from the release of a secret video from a private fundraiser in May in which he disparaged Obama supporters as dependent on government.
In a potential headache for the former business executive, a "Super PAC" group which backs him by funding negative advertising against Obama reported it had plowed through $21.2 million in August while its fundraising declined for the second month. That raised questions about its ability to be an ad-buying force in the final weeks before the November 6 election.
Romney's campaign has also been subjected to infighting and some Republicans have complained that he needs to campaign more.
The latest Reuters/Ipsos poll showed the challenge that Romney faces after one of the most difficult stretches of his campaign. Obama solidified a 5-point lead among likely voters, 48 percent to 43 percent for Romney. Surveys show Romney behind in some of the key states he needs to win on November 6.
"The Romney campaign is being out-hustled and the president's campaign is getting away with this argument that the economy is better off than it was four years ago," said a veteran Republican strategist who has worked on several presidential campaigns.
The Romney campaign says its candidate will spend more time at events with voters, and on a reset of his bid for White House. The campaign promised earlier this week that the former Massachusetts governor would be more specific on policies in an effort to get back on track.
The Obama campaign accused Romney of taking the Washington insider comment "wildly out of context."
"What the president said today is no different than what he has been saying for many years - that change comes from outside Washington, not inside," said Obama campaign spokeswoman Lis Smith.
The backdrop to the fight was Florida, a state with a broad mix of retirees, blue-collar workers and Hispanics. Obama won it in 2008 and could land a severe blow on Romney this year if he can repeat the victory in November.
He leads the polls in Florida despite high unemployment and a struggling economy, evidence that Obama may be winning the argument over whether the country is better off now than it was four years ago.
Obama attacked Romney over his secretly taped video speech in which the Republican said 47 percent of Americans pay no federal income taxes and are unlikely to vote for him.
"When you express an attitude that half the country considers itself victims, that somehow they want to be dependent on government, my thinking is maybe you haven't gotten around a lot, because I travel around the country all the time and the American people are the hardest working there are," Obama said.
He told Univision that his inability to overhaul U.S. immigration laws was the biggest shortcoming of his first four years in office, but he blamed Republican lawmakers for standing in the way.
Pressed on why he had been unable to fulfill a 2008 promise and achieve a comprehensive overhaul of the U.S. immigration system, Obama said the goal also fell victim to his top priority of preventing the collapse of the U.S. economy when he took office.
"I have never wavered in my support of comprehensive immigration reform," he said.
The three presidential debates between the Romney and Obama in October will be critical to the outcome. Romney engaged in some debate preparations in Miami before flying to Sarasota.
Romney's campaign announced plans for him to step up the pace of his campaigning in battleground states.
He will participate in a three-day bus tour of Ohio next week with his vice presidential running mate, Representative Paul Ryan. He will visit Nevada on Friday.
Many Republicans have expressed frustration at the pace of Romney's campaign. A Miami rally on Wednesday was his first public event since a campaign event in Ohio last Friday.
(Editing by Alistair Bell and Mohammad Zargham)