DELRAY BEACH, Fla. -- The campaign sprint to Election Day began Tuesday, promising to follow a changing path to victory that's winding through states where President Barack Obama's once-healthy lead has been shrinking.With 13 days left and the final debate over, 14 states could swing either way, according to polls and analysts. Obama carried 12 of them in 2008, and the issue most on voters' minds is the economy, an issue where Republican challenger Mitt Romney has an edge.A candidate needs 270 electoral votes to win, and two of the biggest prizes, Florida and North Carolina and their combined 44 electoral votes, are trending toward Romney. Five others Obama badly needs -- Virginia, New Hampshire, Iowa, Colorado and Nevada, with 38 electoral votes -- are too close to call.The president is maintaining his lead in Ohio, which every president since 1964 has won. But his lead for its 18 electoral votes is shrinking. More troublesome for Obama could be tightening races in states with 56 electoral votes he counted heavily on winning: Pennsylvania, Michigan, Wisconsin and possibly Minnesota. Romney faces that kind of threat only in Arizona and Montana, which have 14 electoral votes.Obama is still in a good position to win most or even all of these battlegrounds, but at the moment the Romney crowd is more upbeat. Senior Romney adviser Kevin Madden talks about how Pennsylvania is "coming into view," and how Minnesota is "one we have to watch closely."In the Obama camp, senior adviser David Axelrod is almost defiant. "No, no, no," he said when asked about Minnesota and Pennsylvania. "Will we win some states by the same margins as last time? No. But in about every case in those battleground states, you'll find conflicting polls."The biggest trouble sign for Obama is his job approval rating's struggle to top 50 percent. That signals political danger, said David Paleologos of the Suffolk University Political Research Center.The economy is by far the campaign's biggest issue, and "the economy has not changed significantly," he said. The fight between Obama and Romney has become "the economy versus the other issues."