WASHINGTON (AP) -- Republican challenger Mitt Romney looks to use Wednesday's debate against  Barack Obama to revive his struggling presidential campaign, seeking not only to win over undecided voters but also fire up Republicans who have begun questioning whether he can win.
 
   Though polls show the race remains tight ahead of the Nov. 6 vote, Obama clearly has momentum and the edge not only in national polls, but in the battleground states that will effectively decide the election. In some states, Republican candidates appearing on the ballot with Romney have taken steps to establish independence from him.  Party strategists predict more will follow, perhaps as soon as next week, unless Romney can dispel fears that he is headed for defeat despite the weak economy that works against Obama's prospects.
 
   Recent public polls show Obama moving out to a modest lead in most if not all of the battleground states where the race will be decided. But Republicans with access to Romney's polling data said Tuesday that he has begun regaining some support among independent voters, enabling him to cut into the president's advantage.
 
   Because the presidential election is not decided by popular vote but rather by in a state-by-state contest, a handful of so-called battleground states, which do not reliably vote either Republican or Democratic, will likely decide the race.
 
   But it is unclear how long congressional candidates are willing to wait for a turnaround. Several Republican strategists point to this week, which includes the debate and Friday's release of September unemployment figures.
 
   Some Republicans who are in periodic contact with the campaign say Romney's strategists have concluded that a recent uptick in public optimism, coming on top of Obama's success to date, complicates the attempt to defeat the president solely on the basis of pocketbook issues.
 
   In recent days, Romney has emphasized criticism of the president's foreign policy, particularly in the Middle East, where a terrorist attack at the U.S. Consulate in Benghazi, Libya, left Ambassador Christopher Stevens and three other Americans dead.
 
   Former Mississippi Gov. Haley Barbour, who headed the Republican Party when it won control of Congress in the 1990s, said disapprovingly over the weekend that Romney's campaign has been focusing on polling, political process and campaign management. ``It's about everything but the issues. It's about everything but Obama's policies and the failures of those policies,'' he said.
 
   Barbour, echoing what others say privately, was dismissive of the suggestion that Romney should spread his campaign focus. The public is ``concerned about how backwards the Middle East has gone during the last year. But they're much more concerned about their children having jobs, about them being able to pay for their health insurance, for $3.85 gasoline,'' he said.
 
   Privately, Republican strategists also agreed with Barbour's public statement that Romney's campaign has been unable so far to settle on a single, overarching theme to tie together its advertising, the rhetoric of its candidate and appearances by surrogates.
 
   Many of the Republicans who commented on the race declined to be identified by name, saying they were not authorized to speak publicly about strategy.
 
   In one statement emailed on Monday, the campaign quoted Vice Presidential candidate Paul Ryan as telling WTJM in Milwaukee: ``This election is a clear choice between different paths.''
 
   That was close to what the Obama campaign wants, and considerably different from Romney's earlier insistence that the race is a referendum on the president's performance in office.
 
   Already, there are examples of concern from Republican candidates in other races, some subtle, others less so.
 
   In Arizona, Rep. Jeff Flake recently began airing a commercial that accuses Democrat Richard Carmona of being Obama's ``rubber stamp,'' a candidate whom the president recruited to run for the Senate to ``help push his agenda.'' The ad doesn't say so, but Obama would need support in the next Congress only if he defeats Romney this November and wins four more years in the White House.
 
   In North Dakota, Rep. Rick Berg, also running for the Senate, promises in an ad he will ``serve as a check on Obama's failed policies'' by fighting to repeal Obamacare, reduce government regulation and scale back the debt.
 
   Both men are favored to win their races, taking place in states that Romney is expected to carry.
 
   Nervousness first surfaced publicly among Republican Senate candidates two weeks ago, with the disclosure of a video of Romney saying 47 percent of Americans pay no income taxes and a like percentage view themselves as victims who are entitled to government benefits. As a candidate, he said, ``my job is not to worry'' about them.
 
   Linda McMahon, making a second try for a Senate seat from Connecticut, quickly expressed a different opinion. ``I disagree with Governor Romney's insinuation that 47 percent of Americans believe they are victims who must depend on the government for their care,'' she said in a statement released by her campaign.
 
   Appointed Sen. Dean Heller, in a competitive race in Nevada, said, ``My mom was a school cafeteria cook, so I have a very different view of the world than the one Romney expressed.''
 
   Former Wisconsin Gov. Tommy Thompson, running for the Senate, said, ``The presidential thing is bound to have an impact on every election.'' His remark produced a rebuttal from former New Hampshire Gov. John Sununu, a top Romney surrogate, who said: ``My good friend Tommy Thompson sounds like Barack Obama, blaming it on somebody else.''
 
   Obama leads in many of the nine battleground states that will decide the election, and all but two of those states have early voting, meaning more people are already locking in their votes every day. The most important of those states, Ohio, started early voting Tuesday.
 
   Neither candidate had public events Tuesday as they studied for a debate that will focus largely on the economy and other domestic issues.
 
   Romney contends his top issue is strengthening the U.S. economy and creating jobs, issues that are most important among voters. But the former Massachusetts governor is also attacking Obama on foreign policy after Muslim anger over an amateur anti-Islam film made in the U.S. sparked violent attacks on U.S. diplomatic missions.
 
   ``For the last four years, we've had a foreign policy led by a president who believes that the strength of his personality is going to get people to do the right things. Well, we've seen fires burning in U.S. embassies around the world,'' Romney told voters in Colorado on Monday night, echoing a column he published in The Wall Street Journal that day.
 
   The Obama campaign called Romney's foreign policy stances ``incoherent.''
 
   Though Romney's campaign once talked about nothing but the still-weak economy, the multimillionaire businessman recently has turned to other subjects, including wealth distribution, as he has looked for any chance to gain ground.
 
   Romney brought up immigration in an interview published Tuesday by The Denver Post in Colorado, saying he would honor temporary work permits for young illegal immigrants who were allowed to stay in the U.S. because of an Obama administration decision this year.
 
   The candidates are fighting a heated battle for Colorado, whose significant Hispanic population could determine who wins the state. The state-by-state contests determine the election winner, not the national popular vote.
 
   Romney earlier this year was aggressive on immigration, saying he approved of ``self-deportation,'' where illegal workers would choose to leave the U.S. on their own. He also said he would veto legislation to provide a path to citizenship for some of the young people who will benefit from Obama's decision.
 
   Obama campaign spokesman Gabriela Domenzain said Romney's statement to the Denver Post ``raises more questions than it answers,'' including whether he would repeal Obama's policy or deport those who have received a deferment after two years.
 
   Obama retreated Tuesday to a desert resort in Nevada for three days of intensive debate preparation. Top advisers are focused on helping him trim his often-lengthy explanations. Equally important is coaching Obama to look calm and presidential during an expected onslaught of criticism from Romney. 
 
   Romney spent more than eight days in September holding mock debates. He planned another day of preparation Tuesday at his hotel in Colorado, the site of Wednesday's debate.
 
   Both campaigns dispatched the candidates' wives and running mates to rallies Tuesday. Romney's running mate, Rep. Paul Ryan, was asked about the secretly taped video released last month of Romney telling donors that he would never persuade the 47 percent of Americans who support Obama to ``take responsibility'' for their lives. The Obama campaign continues to bring it up to paint Romney as out of touch with average Americans.
 
   ``Sometimes the point doesn't get made the right way,'' Ryan said.