HARRISBURG, Pa. - So much for Mitt Romney's plans to compete for Democratic-trending Michigan or Pennsylvania. And what about President Barack Obama's early hopes of fighting it out for Republican-tilting Arizona, Georgia or Texas? Forget them.

The presidential battleground map is as compact as it's been in decades, with just nine states seeing the bulk of candidate visits, campaign ads and get-out-the-vote efforts in the hunt for the 270 Electoral College votes needed for victory. That means just a fraction of Americans will determine the outcome of the race for the White House.

"It's difficult if not impossible to pull new states into that kind of competition," said Tad Devine, a Democrat who long has helped his party's presidential nominees craft state-by-state strategies to reach the magic number.

A month before Election Day, that means both candidates are concentrating their precious time and money in the handful of states that still seem to be competitive: Ohio, Florida, Nevada, Colorado, Iowa, Virginia, North Carolina, New Hampshire, and Wisconsin.

Obama succeeded in expanding the map in 2008 by winning the traditionally Republican states of Indiana, North Carolina and Virginia. But it took a Democratic tidal wave to do so, and he was the exception in a nation that's grown increasingly polarized, with demographic shifts heralding Democratic victories in the Northeast and on the West Coast and Republican dominance in the West and South.

"Politics in the country has become homogenized regionally and culturally," said Steve Schmidt, a veteran of Republican presidential campaigns. So, he added: "You're left with the only states that have the population and demographic mix where it's in question who is going to be on top at the finish line."

TV ad money - the best measure of whether a campaign is competing in a state - shows that 93 percent of the $746 mil