Jim Wilson/The New York Times
As Mr. Obama opened a two-day bus tour of Florida on Saturday and Mr. Romney set his sights on trying to put Virginia back in the Republican column, television ads from both sides were filling the airwaves in those two vital states and six others from Nevada to New Hampshire, while outside groups supporting the candidates tested for traction elsewhere.
With the political conventions over, the battle to determine whether Mr. Obama will win re-election or Mr. Romney will become the 45th president of the United States is fully engaged. The race has been deadlocked according to many measures, and each side was predicting that it would see no lift from its convention. That seems to have been true in Mr. Romney’s case, and Mr. Obama’s aides were hopeful that new polls due out this week would prove them wrong.
But for now Mr. Obama may hold a slight edge because the race remains essentially tied, which means voter disappointment has not turned into a resounding call for his defeat despite the challenging economic climate.
Presidential races take place on many levels, some easily visible, others more shrouded. As the clock runs down, both sides make tough decisions about which states to compete in and which to abandon. Advertising messages get tested and changed as strategists hunt frantically for the right appeals, and get-out-the-vote teams wavering voters with tailored messages.
Behind closed doors, the candidates are preparing for the most crucial remaining events, the debates. And in courtrooms, lawyers battle over who is on the ballot and who can vote.
The race could also still be influenced by unforeseen events, domestic or foreign, that could shape perceptions of the incumbent president and his challenger. Here are a few things to watch in the 58 days ahead, beginning with the electoral map.
The roster of battleground states has not changed much, but one that Republicans had dearly hoped to put in play appears to have broken decisively: Pennsylvania. Mr. Romney spent time and money in the state, which went Democratic in the last five presidential elections, but Republican strategists now say it seems out of reach.
At this point in the campaign, Mr. Romney had hoped to put at least a few more states into safer Republican territory. North Carolina, which Mr. Obama narrowly carried in 2008, is at the top of the list. But the state is still competitive enough that Mr. Romney and Republican groups feel compelled to keep spending on advertising there, complicating their hopes of making Wisconsin and Michigan more competitive.
Some Democratic strategists say winning Florida remains a reach for Mr. Obama, but his presence there this weekend suggests that the White House has not given up and at a minimum will make Mr. Romney spend a lot more time and money there.
And Democrats say they are happily surprised by polls showing Mr. Obama running strong in Ohio, whose working-class voters have been exposed to heavy advertising portraying Mr. Romney as a job killer.
In a race that has featured little significant movement between the candidates, the three debates this fall are taking on even greater importance.
For weeks, Mr. Obama and Mr. Romney have been preparing for their encounters on Oct. 3 in Denver; Oct. 16 in Hempstead, N.Y.; and Oct. 22 in Boca Raton, Fla.
With each passing debate, millions of Americans will probably cast their ballot, given the rise of early voting and vote-by-mail in many Western states.
The president, whose advisers know him to procrastinate before preparing for big moments, has been studying his rival’s positions and statements from the primary campaign. Senator John Kerry of Massachusetts will play the role of Mr. Romney in debate practice.
Mr. Romney may be a little further ahead in his preparations. His aides began putting blocks of debate-preparation time into his schedule shortly after he emerged from the primaries in the spring. He started formal practice sessions last week at a remote estate in Vermont, where Senator Rob Portman of Ohio played the role of Mr. Obama.
Four years ago, viewership for the debates ranged from 52 million to 63 million people — a much bigger audience than the ones that tuned in to the conventions this year.
Ads and Messages
After spending the spring and summer trying to turn Mr. Romney’s success as a business executive from a positive to a negative, characterizing him as uncaring about the middle class, Mr. Obama’s aides and allies intend to graft their portrayal onto specific policy areas.
They suggested that one attack, building on the president’s argument that Mr. Romney intends essentially to privatize Medicare, would contend that the Republican ticket’s next target would be another immensely popular program, Social Security.
In the past, Mr. Ryan has supported adding personal investment accounts to Social Security, a fundamental shift in the program that most Democrats say would leave the elderly vulnerable to unpredictable swings in the financial markets.
Having intently studied the 2004 race, when President George W. Bush won re-election after defining Senator Kerry on his terms during the spring and summer, Mr. Obama’s advisers are convinced that the most crucial advertising period of the campaign is already over, and that they accomplished what they had to by introducing Mr. Romney to the nation as a rapacious capitalist.
Mr. Romney’s team is betting that early ad spending is largely wasted, and that a final and furious campaign will move the race in his direction when it most counts, at the end. The campaign’s belief is that continued disappointing economic data will feed its slogan, “Obama Isn’t Working,” and give a new edge to the question Mr. Romney is posing at every opportunity: “Are you better off than you were four years ago?”
On Saturday, the Democratic “super PAC” Priorities USA Action released an advertising campaign highlighting a study by the nonpartisan Tax Policy Center that estimated Mr. Romney’s plans would raise taxes on the middle class while cutting them for the wealthy. Mr. Romney’s campaign has said the finding is based on flawed assumptions.
Like the Democrats, Republicans say they intend to link their broader economic message to specific policies: cutting spending and reducing the national debt, working to ensure the solvency of Medicare for future generations, cutting expensive regulations and avoiding tax increases.
Over the next two months, swing-state residents will see ads on the local issues that matter most to them: foreclosures in Nevada, Medicare in Florida, military spending in North Carolina and Virginia, and, especially from the Republican side, the federal budget deficit just about everywhere.
Mr. Obama and his supporters are telegraphing a new campaign to paint their opponents as pessimists “betting against America,” as Vice President Joseph R. Biden Jr. put it on Thursday night.
“They are extremely pessimistic because they want to tamp down people’s enthusiasm about the future,” said Representative James E. Clyburn, Democrat of South Carolina.
But if Democrats go too far in that direction, Republicans will be ready to pounce and call them out of touch with reality.
There is one factor in the campaign that has yet to get much attention but could influence the outcome: third-party candidacies in many states, most notably that of former Gov. Gary Johnson of New Mexico, the Libertarian Party’s presidential nominee.
Mr. Johnson, who advocated free markets, fewer wars and the legalization of marijuanaduring his brief run for the Republican nomination, hardly shows up in polls. But he is on more than three dozen state ballots and trying for more.
Mr. Johnson shares some of the cross-party appeal of Representative Ron Paul of Texas, who complimented him publicly last week. Advisers to Mr. Johnson said he had the most potential to cut into Mr. Romney’s support in Florida, where Mr. Romney is basically tied with Mr. Obama now, and to have an impact in Nevada, New Hampshire and Arizona.
They said he had the most potential to eat into Mr. Obama’s support in New Mexico, Colorado, Iowa, Oregon and Wisconsin.
Republican officials have already tried to, or are preparing to, challenge Mr. Johnson’s place on the ballot in Pennsylvania, Virginia, Ohio, Iowa and Michigan. Many of the challenges have failed — courts recently rejected efforts to throw him off the ballot in Virginia — and Roger Stone, a Republican Party veteran who is advising Mr. Johnson, said he was optimistic that Mr. Johnson would make it onto the ballot in all 50 states.
The Republican Party of Virginia also failed in a bid last week to remove former Representative Virgil Goode from the presidential ballot there. He is the nominee of the Constitution Party, and could draw disaffected Tea Party adherents away from the Republican Party.
For the first time since the advent of public financing after Watergate, neither major-party candidate will accept matching funds, forcing both to keep raising money right up to Election Day. That means Mr. Obama and Mr. Romney have to build substantial room into their schedules for fund-raising, including more time than they would like traveling to places that are not competitive politically but are flush with wealthy donors, starting with New York and Los Angeles.
At the end of July, when the last official figures were available, Mr. Romney and the related Republican Party presidential committees had about $186 million on hand, compared with about $124 million for Mr. Obama and the Democrats.
Mr. Obama’s advisers have expressed concerns that the Romney war chest, combined with well-financed Republican super PACs, will swamp them and Priorities USA Action when it comes to advertising. But much of the Obama campaign’s money is going into its sophisticated voter-identification and get-out-the-vote operation, which is fully up and running while Mr. Romney rushes to build his own.
“We have a strategic advantage on the ground — the ability to turn our voters out and talk to persuadable voters — and that’s what we’re going to do,” said Jim Messina, the Obama campaign manager.