DAYTON, Ohio -- The endgame at hand, President Barack Obama and Republican Mitt Romney entered the final two weeks of a close race for the White House Tuesday with TV advertising nearing $1 billion as millions of Americans cast early ballots in all parts of the country.
Ohio increasingly looms as ground zero in the campaign. The state's unemployment rate of 7 percent is well below the national average of 7.8 percent. Obama has campaigned here more than in any other state, and Romney has booked a heavy schedule of appearances in hopes of a breakthrough.
Obama brandished a new 20-page summary of his second-term agenda and told a campaign crowd in Florida his rival's blueprint "doesn't really create jobs. His deficit plan doesn't reduce the deficit; it adds to it."
And he said Romney changes his positions so often he can't be trusted.
In Dayton, Obama said of his rival: "In the closing weeks of the campaign, he's doing everything he can to hide his true positions. He is terrific at making presentations about stuff he thinks is wrong with America, but he sure can't give you an answer about what will make it right. And that's not leadership you can trust."
Before flying to Ohio for his 17th trip of the election year, Obama also said with a hint of humility: "It doesn't mean that every candidate is going to get everything done all at once perfectly, but you want somebody to be able to look you in the eye and say, here's what I believe."
Romney countered in an appearance in Henderson, Nev. He said Obama wants a new term for the same policies that have produced slow economic growth and high unemployment for four years. "He is a status quo candidate. ... That's why his campaign is slipping and ours is gaining so much steam," he said.
Material collected by ad trackers showed the candidates and allied groups have spent or reserved nearly $950 million so far on television commercials, much of it negative, some of it harshly so.
Romney and GOP groups had a $100 million advantage over Obama and his supporters, although variations in the purchase price made it difficult to compare the number of ads each side had run.
The campaigns were focused on turning out their supporters in early balloting under way in more than half the states.
About 5 million voters already have cast ballots according to data collected by the United States Elections Project at George Mason University, and about 35 million are expected to do so before Nov. 6.
Democrats have cast more ballots than Republicans in the battleground states of North Carolina and Iowa by about 20 percentage points, while in Nevada, about 121,000 people have voted -- 49 percent Democrats and 35 percent Republicans.
Republicans have an early edge in Colorado, where Republicans have cast 43 percent of the 25,000 ballots to date, to 34 percent for Democrats.
Electoral College math made clear neither man had sealed a victory.
Wins in Ohio and in Wisconsin -- a state that Democrats have carried in the past six presidential elections -- would leave Obama five electoral votes short of 270 needed for victory.
That placed a premium on Ohio -- readily apparent from the candidates' schedules and aggressive television spending.