State elections officials had no reports of early problems on Super Tuesday as Ohio polls opened, some to light voter turnout, in a state where the outcome in the Republican presidential race was being closely watched.
Mitt Romney and Rick Santorum devoted most of their campaigning to Ohio in the last days before the 10-state primary voting. Romney was looking for a decisive victory, while Santorum hoped to regain momentum in his chase. Former House Speaker Newt Gingrich also was hoping to pick up some delegates, while banking his comeback hopes on winning Georgia.
In the Columbus suburb of Westerville, Romney got a vote from textbook editor Heather Froelich, a registered Republican who said she likes Romney's business background and believes he has the best chance to beat President Barack Obama in November.
"I know that he understands the economy," said Froelich, 40. "He has the right experience and values."
Republican Josh Brooks of Columbus said he had considered voting for Romney, but Gingrich won him over with his energy plan for lowering gas prices.
"He's tough and he's got big ideas," the 32-year-old engineer said.
Others voters said they weren't impressed with their options or how the Republican candidates had attacked one another.
"It's going to make me vote Democratic," said Chuck Horning, a 47-year-old accountant and one of the earliest voters at a polling site in the Cincinnati suburb of Anderson Township, a heavily Republican area.
He said he was so disappointed that he voted only on local issues, not in the presidential primary.
"It is a painful process this year," he said. "I don't like the way the Republicans have gone after each other, and the Democrats aren't any better."
At the same site, self-described independent George Knoske, 48, said he voted for Republicans in the past but backed Obama, a Democrat, on Tuesday. Knoske, who works in computer technology, said the 2012 GOP candidates didn't grab his attention.
"They are not enough toward the middle for me," he said.
The Ohio Secretary of State's office didn't forecast a turnout, but some polling sites had few people show up in the first hours of voting, though things appeared to pick up later in the morning.
Besides presidential contenders, voters have plenty of choices to make. Those include an unusual match of two Democratic U.S. House members pushed together under congressional redistricting, and a contested primary for the Republican nominee to oppose Democratic U.S. Sen. Sherrod Brown.
Ohio Treasurer Josh Mandel has a well-funded effort to take Brown's seat back for Republicans after the Democrat's 2006 victory. But Mandel first has to overcome five other Republicans.
And northern Ohio Democrats must choose between veteran incumbents Marcy Kaptur and Dennis Kucinich, while four Democrats are vying for a new district that includes most of Columbus. The state's congressional map was redrawn because Ohio loses two House seats because of population changes reflected in the 2010 census.
Meanwhile, a Toledo-area plumber thrust into national politics during the 2008 presidential campaign is running for the Republican nomination for the northern Ohio 9th House seat. Samuel Wurzelbacher became known as "Joe the Plumber" for expressing working-man concern about taxes to then-candidate Barack Obama.
Democrats hoping to tap into Ohio voter discontent with Republican efforts to restrict public employee collective bargaining are among the legislative candidates. There are 14 Democratic and 18 Republican primaries for House seats, and three Republican primaries for state Senate seats. Voters overwhelmingly repealed the Republican-passed union law last November, giving hope to Democrats challenging the Republican majority in November.
Two experienced judges were in the Democratic primary to challenge incumbent Justice Robert Cupp this fall, and some 100 local school issues are on ballots across the state as districts grapple with funding issues.
Ohioans are used to election attention in a big swing state that tests candidates with its geographic and economic diversity. Voters are spread among cities, small towns, farmland, swaths of suburbs and Appalachian hills, working in Rust Belt manufacturing, agriculture, medical and high-tech businesses.
No Republican nominee has reached the White House without carrying Ohio. Obama carried the state in 2008, after it delivered George W. Bush's clinching re-election votes in 2004.
Lying between Romney's native Michigan and former U.S. Sen. Santorum's home state of Pennsylvania, Ohio appeared to be a toss-up in recent polls.
Polls have tracked voter volatility among Ohio Republicans. Pizza magnate Herman Cain, Gingrich and Santorum have all leapfrogged past Romney only to fall back in the last six months. Late polls also indicated that significant numbers of likely Ohio primary voters said they might change their minds once they were casting their ballots.
Santorum planned to watch returns Tuesday night in Steubenville, in eastern Ohio.
Associated Press writers Lisa Cornwell in Cincinnati, Ann Sanner in Westerville and Kantele Franko in Columbus contributed to this report.
Contact Sewell at http://www.twitter.com/dansewell