Secretary of State Kenneth Blackwell won the GOP nomination for governor Tuesday after campaigning as the best candidate to deliver his party from a year of political scandals and infighting.

The Republicans' woes, along with Ohio's role as the deciding state in the last presidential election, turned the primary into a closely watched barometer of voter dissatisfaction and whether it could lead to political upheaval in November.

"The Republicans have a problem," said Carl Rullmann, a GOP voter who said he supported Blackwell.

With 90 percent of precincts reporting, Blackwell had 421,337 votes, or 56 percent, compared with 325,162, or 44 percent, for Attorney General Jim Petro.

Two other states also held primaries Tuesday, including North Carolina, where the district attorney prosecuting the Duke University rape case fought off two challengers, and Indiana, where congressional incumbents easily won their party nominations.

Blackwell's prominence as a leading black voice in the GOP could be pivotal to Republicans. He is the first black candidate to run for governor in Ohio. His ads sought to taint Petro with connections to the state's investment in rare coins that went awry and to tie him to Gov. Bob Taft, who pleaded no contest to four ethics violations last year involving a failure to report free golf outings and gifts.

Petro hammered Blackwell as a hypocrite who opposes abortion and gambling even though some of his multimillion-dollar stock portfolio is invested in those interests.

The GOP disunity may have turned off some voters.

"I saw a lot of backstabbing, name-calling, character assassination. I don't go for that kind of stuff," said James Martin, 66, leaving a polling place in the Cleveland suburb of Strongsville. He said the negative campaigning influenced his choice in the Republican primary, but he would not say who that was.

Blackwell gained fame as the Republican chief elections official in Ohio in 2004, when the state returned President Bush to the White House. Blackwell also served in the Reagan administration and is known for carrying a Bible to events.

The Ohio scandals emboldened Democrats who hope to end the Republicans' 15-year hold on the governor's office.

The winner of the primary will face Democratic U.S. Rep. Ted Strickland in November. Strickland is viewed as the Democrats' best chance to regain some control over a state government where Republicans control all three branches, as well as statewide offices and a majority of congressional seats.

Strickland handily defeated a former state legislator for the nomination. With 90 percent of precincts reporting, he had 527,594 votes, or nearly 80 percent.

Republicans targeted the House seat Strickland leaves open as one of its best shots nationally to gain a Democratic congressional spot. The Democrats' leading candidate won, despite having to run as a write-in due to a filing mistake. National Democrats and Republicans spent roughly $1 million in the race, more than they have for any primary in the past decade.

Ohio's U.S. Senate race will also be closely watched in the fall, but incumbent Sen. Mike DeWine and his Democratic rival, U.S. Rep. Sherrod Brown , easily emerged from the primary.

It was the first election in which all 88 Ohio counties used either touch-screen electronic voting machines or optically scanned paper ballots.

Some results were delayed after Blackwell told election boards not to release them until all polls had closed. He issued the order after a judge kept a Cleveland polling place open late because it had not opened on time.

In North Carolina, rape allegations against Duke athletes turned what might have been a low-key election into a referendum on Mike Nifong's performance.

In unofficial results, Nifong had 45 percent of the vote, with challenger Freda Black close behind with about 42 percent. There are no Republicans running in the general election, and Nifong needed only 40 percent of the vote to avoid a runoff.

Also in North Carolina, former NFL and University of Tennessee quarterback Heath Shuler easily won the Democratic nomination for U.S. House in the state's far western 11th District, setting up a November contest against longtime GOP Rep. Charles Taylor .

In Indiana, all nine congressional incumbents advanced to the November election. Most challengers were short on money and party support. Sen. Richard Lugar , one of the most popular politicians in state history, had no Republican opposition.