"We have seen a slight Democratic advantage in key districts in early and absentee votes," said Wes Anderson, a Republican pollster who has conducted surveys in congressional races in Ohio. "Those who have yet to vote are clearly trending Romney's way. The question is, is this movement toward Romney happening fast enough and big enough to overcome the slight deficit that he now has in early voting."
Romney advisers say they see signs that outside the big, populous counties, Romney could benefit from a wave of conservative voters as President George W. Bush did in 2004.
"Rural counties are really coming home," Romney political director Rich Beeson said. "You see it in early absentee and you see it in the intensity level. That's where we're going to make some ground."
Obama aides say the early turnout in Ohio is higher in counties that voted for him in 2008 than it is in precincts that voted for Republican John McCain that year.
Yet, a number of counties where Obama won four years ago, including Hamilton County in the Cincinnati suburbs, Stark County south of Cleveland and Portage County where Kent State University is located and where Marsilio is a commissioner, voted for Republican Gov. John Kasich and Republican U.S. Sen. Rob Portman in 2010.
Besides Ohio, the eight other battlegrounds where the candidates are spending time and money are Colorado, Florida, Iowa, Nevada, North Carolina, New Hampshire, Virginia and Wisconsin.
So far, Democratic voters casting early ballots outnumber Republicans in Ohio, Florida, Iowa, North Carolina and Nevada. Republican voters have the edge in Colorado. No votes will be counted until Nov. 6, but several battleground states report the party affiliation of people who have already cast ballots. Some, like Ohio, have large blocs of unaffiliated voters.
In North Carolina, more than 1.5 million people have cast ballots, 50 percent of them Democrats and 31 percent Republicans. In Iowa, about 471,000 people have already voted — 45 percent Democrats and 32 percent Republicans. About 433,000 voters in Nevada have cast ballots, 45 percent Democrats and 37 percent Republicans.
In Florida, about 1.8 million voters have cast ballots and Democrats have edged in front of Republicans, 42 percent to 41 percent, according to a tally by the AP. Republicans had the early lead among people who voted by mail, but the Obama campaign has made a big push since in-person early voting started Saturday.
About 804,000 voters have cast ballots in Colorado, and Republicans have a slight edge over Democrats, 39 percent to 36 percent.
Ohlemacher reported from Washington; Associated Press Senior Elections Research Coordinator Cliff Maceda contributed to this report.
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