Some light turnout as Ohio polls open for primary

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