As Hurricane Isaac approached landfall along the Louisiana coast, President Obama navigated between his roles as candidate and commander in chief Tuesday, seeking votes in swing states and assuring people in the storm’s path that the administration is prepared to respond.

“We’ve been getting ready for this storm for days,” the president told an outdoor crowd at Iowa State University, the first of three scheduled campus stops to shore up support from college-age voters.

“We’ve got response teams and supplies in place. America will be there to help folks recover no matter what this storm brings, because when disaster strikes, we are not Democrats or Republicans first,” he said. “We are Americans first. We’re one family, and we help our neighbors in need.”

But Obama quickly pivoted to his stump speech, assailing challenger Mitt Romney’s plans to roll back his health-care law, nicknamed Obamacare, and lower taxes on the wealthiest Americans.

“Maybe we should call his plan ‘Romney Doesn’t Care,’ ” he said. “Because I do care. And this law is here to stay.”

Isaac, upgraded from a tropical storm to a Category 1 hurricane at midday Tuesday, poses thorny political challenges for Obama and Romney.

For Romney, it means the nation’s attention is likely to be divided as he takes his once-in-a-campaign opportunity to introduce himself as the Republican presidential nominee. Moreover, as Gulf Coast residents contend with the storm, Romney will be speaking as the standard-bearer for the party whose last president led the calamitous response to Hurricane Katrina in 2005. He will have to strike a delicate balance: outlining his political case against Obama while conveying awareness of and empathy for those suffering as a result of the storm.

For Obama, the politics are higher risk — and higher reward. He will need to respond aggressively and effectively to Isaac while avoiding perceptions that he is exploiting the moment. If the relief effort is botched, it could deal him a blow in the race, which is locked in a statistical dead heat.

Both camps spent Tuesday dealing with the politics of Isaac.

As Romney and his family landed in Tampa, all indications were that he was prepared to forge ahead with a convention already squeezed from four days to three because of the storm. Adviser Eric Fehrnstrom said he did not plan to make an issue of Obama’s response to Isaac.

“We don’t view the weather as political, and certainly a storm of this magnitude deserves the attention of the president of the United States,” Fehrnstrom said.

As the Republican National Convention opened in earnest Tuesday afternoon, participants offered quick but respectful tributes to those at risk from the storm — then turned swiftly to politics.

“I’d like to offer our thoughts and prayers for the safety of those in the path of the hurricane,” Republican National Committee Chairman Reince Priebus said before returning to the business at hand: the disassembling of Obama’s presidency and the introduction of Romney as the solution to the nation’s problems.

On the convention floor, delegates also sounded sympathetic but focused on politics.

“Nobody likes a hurricane,” said Bob Rucho, a North Carolina state senator. “Of course we pray that the least amount of damages and no death or casualties occur.” But he added that he doesn’t expect it to affect the convention. “We’re very upbeat about this,” he said. 

Rhode Island delegate Doreen Costa said that Republicans are ready to respond to the storm by raising money but that any talk of a cloud over the convention is a creation of the Democratic opposition.

“We still have to think about the people who are in New Orleans and the hurricane, and of course the left will be saying [the convention] should have been canceled — and would they have canceled theirs? Probably not,” she said.

Isaac aside, presidential candidates have traditionally taken a low profile during their opponents’ nominating conventions. Obama’s decision to campaign during the GOP gathering — and against the backdrop of a dangerous storm — underscores the tightness of the race. His campaign is reluctant to leave anything to chance, particularly in the nine battleground states widely seen as key to winning on Nov. 6. He hit two of them Tuesday with his Iowa State appearance and a speech at Colorado State University in Fort Collins. He will round out the trip Wednesday at the University of Virginia.

In the split-screen political environment created by Isaac, his aides took pains to emphasize that the president could seamlessly handle his dual missions.

“He is also conducting campaign events but . . . will be getting information regularly on the status of the storm and on the status of the federal response,” press secretary Jay Carney said. Later, he said Obama had held a long call with FEMA Administrator W. Craig Fugate, Homeland Security Secretary Janet Napolitano, homeland security adviser John O. Brennan and other top officials.

Campaign spokeswoman Jennifer Psaki left open the possibility that Obama could visit storm-damaged areas later in the week. “As Jay mentioned, the president continues to monitor what’s happening,” she said. “If anything needs to be changed, that is something we will adjust.”

Rachel Weiner contributed to this report.