By JIM KUHNHENN and STEPHEN OHLEMACHER
KENT, Ohio (AP) - Tommie Jo Marsilio is a former union shop steward. She's a single mom. And she's a Mitt Romney voter.
"It's not my job to shatter stereotypes," she says. But she is. Two years ago she became the first Republican elected to the local county commission as part of a Republican wave in an Ohio county that Barack Obama won in 2008.
From the candidates' campaign headquarters in Boston and Chicago, the electorate looks like a series of demographic groups. Voters become bar charts _ women and union members for Obama, men and retirees for Romney, all part of the metrics to measure turnout and make educated guesses about outcome. But on the ground in this battleground of battleground states, with early voting well under way, the reality can complicate the science and generalization.
In a race this close, how well Romney and the president target their voters, sway independent ones and get them to the Ohio polls might well determine the outcome of next Tuesday's election. But people often don't match the voter profiles.
Take John Petelin, a 43-year-old skilled tradesman, a white male who voted for a third-party candidate instead of Obama in 2008.
He might be expected to line up behind Romney. But he isn't.
"I'm an autoworker," Petelin said outside the Lorain County Board of Elections building where he had just voted for Obama. "It's been tough out there. And Romney wanted to kill us. I can't go for that."
Or Kris Donofrio, a mother with three children in college. Standing by her car after voting in Lorain, a north-central Ohio city west of Cleveland, she scoffs at Romney's suggestion that kids can borrow for school from their parents.
But her parents, staunch Democrats she said, are voting for Romney. "They're concerned about Medicare," she said. "They think Obamacare is not for them."
Ohio voters like these are steadily making their way into county polling places across the state, casting early ballots that will determine whether Ohio will serve as a Democratic firewall against Romney's advance or a fire pit where the president's candidacy will perish.
Across the country, about 15 million voters already have cast ballots in the presidential contest, according to the United States Elections Project at George Mason University. In Ohio, about a million have submitted absentee ballots or voted in person.
With just a week left before Election Day, Obama holds some clear edges in Ohio, not the least of which is an advantage in the early vote and a robust get-out-the-vote organization. He holds a narrow lead in some public polls in the state, though others show a neck-and-neck race as the campaign tightens in the homestretch.
Obama's political outreach, built on the broad base of support from 2008, is extensive and frequent. The auto industry, boosted by the government bailout, is resurgent.
In an interview with Cincinnati radio station WIZF that aired on Monday, Obama laid out the early vote strategy.
"We really want to bank as many votes as possible," he said. "So the fewer people who haven't voted yet, the better our Election Day operation is going to be."
But Romney, energized and locked in a dead heat nationally with the president, is mounting his own aggressive voter contact effort, partly counting on the inroads Republicans made in the state in 2010 and seeking to capitalize on discontent toward Obama among many independent voters. In county after county, campaign aides say, more Republicans are taking steps to vote early than did in 2008.
In Ohio so far, Democrats have a 31 percent to 24 percent lead among voters who have cast ballots in 50 of the state's 88 counties, according to data collected by The Associated Press. Forty-five percent of early voters in those counties were unaffiliated.
Those numbers have limitations. Party affiliation is based on the last primary in which someone voted, so new voters and those who don't vote in primaries are listed as unaffiliated.
A poll by Time magazine last week had Obama's advantage over Romney among early voters at 60-30 across the state.
And internal Republican polls also show Obama with leads even in Republican-leaning parts of the state, increasing the burden on Romney to do well on Election Day.
"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."