TAMPA, Fla. (AP) — To the last minute, Florida is proving to be an expensive and frustrating state for President Barack Obama and Republican Mitt Romney alike, seemingly resistant to arguments that play well in Ohio, Colorado and other states. For all the talk of Florida leaning Republican, both nominees are making stops here in the campaign's final 40 hours, a testament to its uncertainty. Their campaigns and allies have poured $130 million into Florida TV ads. Florida is a tough sell for Obama's national message of steady economic recovery, because its unemployment and foreclosure rates remain above the national average. The auto industry bailout ads airing in Ohio would make little sense here. And Obama's standard remarks to Hispanics don't resonate so well in Florida because its two largest Hispanic groups, Cubans and Puerto Ricans, are exempt from immigration laws that Mexican-Americans and others intensely follow. These factors played into Obama's decision to make his strongest battleground stand in Ohio, which has 18 electoral votes to Florida's 29. And they prompted Republicans to hope Romney would lock up Florida early. But a well-organized Democratic ground game, and a population that's increasingly non-white, have given Obama hope of winning Florida narrowly and all but assuring his re-election. "I think it's too close to call," said Jerrold Kronenfeld, 68, an Obama volunteer who attended Friday's rally by former President Bill Clinton in Palm Bay, Fla.