President Obama and Republican challenger Mitt Romney are in a statistical dead heat in Ohio, Virginia and 10 other states up for grabs in the 2012 election, according to a poll released .

The poll by Gallup Inc. and USA Today showed Obama with 47 percent support in the 12 states and Romney with 45 percent, well within the survey's margin of error of 4 percentage points. That is a tighter race than in March, when it found the Democratic president with 51 percent and Romney with 42 percent.

Behind the numbers, however, Obama supporters appear to show stronger support and more enthusiasm for their candidate than backers of Romney, a former Massachusetts governor and business executive who had to fend off a handful of more conservative challengers during his party's nominating process.

Fewer Romney supporters in the 12 "swing states" polled - which also include Colorado, Florida, Iowa, Michigan, Nevada, New Hampshire, New Mexico, North Carolina, Pennsylvania and Wisconsin - said they were certain they would vote for the presumptive Republican nominee. They were also less enthusiastic.

"Romney's position does not appear quite as competitive, however, when one considers that his support is a bit softer than Obama's," Gallup, a national polling firm, said in a statement.

The findings come as Obama officially kicked off his re-election campaign with rallies in Ohio and Virginia six months before the vote. Other polls have also shown a tightening race in some swing states.