WASHINGTON (Reuters) - President Barack 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 on Monday.
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.
Gallup's findings, which did not provide a state-by-state breakdown, also showed more steadfast Obama supporters. About 36 percent of voters in the 12 states said they will certainly vote for Obama on November 6 election, compared to 32 percent for Romney.
The poll, which surveyed a random sample of 951 registered voters between April 26 and May 2, also found that 55 percent of Obama's supporters are extremely or very enthusiastic about voting in the election, up from 49 percent in March.
In comparison, 46 percent of Romney supporters said they were extremely or very enthusiastic about the same as in March, when 47 percent expressed enthusiasm.
Gallup said the findings show a switch from January, when 55 percent of Romney voters were extremely or very enthusiastic compared to 50 percent of Obama voters.
Additionally, the survey found that 11 percent of Obama supporters and 13 percent of Romney voters said they may change their mind before the election. Another 7 percent were undecided.
That leaves 31 percent of swing-state voters at play in the competitive states, Gallup said.
"If Obama's advantage on enthusiasm continues, it could benefit him in voter turnout on Election Day. The key to these patterns, of course, is if they continue," it said.
Editing by Doina Chiacu