CHARLOTTE, N.C. » President Barack Obama is embarking on a four-day march through battleground states and the storm-battered Gulf Coast in the lead-up to his party’s convention as he seeks to blunt any momentum picked up by Republican rival Mitt Romney.

As his party’s faithful began streaming to Charlotte, N.C. for next week’s convention, Obama was returning to Iowa on Saturday. For his part, Romney looked to capitalize on a newly energized Republican Party fresh from its convention in Tampa, Fla., with a rally in Cincinnati before joining running mate Paul Ryan later in the day in Jacksonville, Fla.

Both campaigns were crisscrossing the country as the race entered September, each day adding to the sense of urgency in a presidential contest that has remained tight since Romney sewed up the nomination in April. Both campaigns recognize that undecided elements of the electorate, including those in about eight key states, will begin to fully assess their options through the conventions and the upcoming debates in the weeks ahead.

“Hold us accountable. Listen to what we have to say,” Romney said in a post-convention rally in Lakeland, Fla., on Friday. “I plan on winning in Florida. We love this country and we’re taking it back.”

Obama’s run-up to the convention will take him through the battleground states of Iowa, Colorado, Ohio and Virginia, four states that he carried in 2008 but remain at the top of Romney’s wish list. He was spending Saturday in suburban Des Moines and Sioux City, Iowa, before heading to Colorado for a Sunday event with college students at the University of Colorado in Boulder.

The Democratic Party’s convention, which starts Tuesday in Charlotte, N.C., will focus more on where voters want their lives to be in the next four years. Obama inherited an economy grappling with a sweeping recession and the pace of the sluggish recovery has become one of Obama’s greatest impediments to re-election.

The coming days, capped by Obama’s speech on Thursday night, will crystalize his re-election pitch: an economy built on ending tax cuts for the rich and putting more effort into education, energy, tax reform and debt reduction. He will call Romney a peddler of failed trickle-down ideas that will hurt the middle class and the needy.

Previewing the convention, Obama campaign aide Stephanie Cutter said the Charlotte gathering wouldn’t be about rallying the base or leveling “petty attacks” but would instead focus on “what we need to do with the country to move us forward, not back.”

“We don’t need to reintroduce the president or reinvent him, as in the case with Mitt Romney,” she said. “Instead, our convention will tell the story of the last four years, how the president made some tough choices to help a country and the economy recover.”

Both sides hope to convey the aura of leadership.

Romney made a quick detour to rain-soaked Louisiana on Friday while Obama joined soldiers at Fort Bliss, Texas, to remind the nation that he ended the war in Iraq. Obama was scheduled to travel to Louisiana on Monday to inspect flood damage in a storm that marked the seventh anniversary of Hurricane Katrina’s devastation.

Romney was capping his convention week in Ohio and Florida, the two most prominent states that remain up for grabs. The former Massachusetts governor’s team said the Tampa, Fla., convention helped him present a clear contrast with Obama and showcase him as a viable alternative to the president on handling the economy.

“What Americans have seen over the last few days is a party and a Republican ticket absolutely committed to addressing the job crisis,” said Romney adviser Eric Fehrnstrom. “You won’t hear it from the Democrats in Charlotte next week. People have seen a diverse group of individuals who believe very deeply in the American free enterprise system. It’s very different than the negative characterization the Democrats are trying to paint of this convention.”

Television ratings for the final night of the Republican convention were down compared with four years ago. The Nielsen Co. said an estimated 30.3 million viewers watched Thursday night’s coverage over 11 networks compared with more than 40 million over seven networks when John McCain delivered his acceptance speech in 2008.

Hunt reported from Cincinnati. Associated Press writer Beth Fouhy in Charlotte, N.C., contributed to this report.