It's Nov. 5, the day after the grueling, bitterly fought presidential election has ended and all the ballots have been cast.

But because of Ohio, no one knows whether Barack Obama or John McCain won. And the mystery stretches on for day after day after day, just like Florida in 2000.

That may not happen, of course. The race in Ohio may not be that close, or the outcome of the presidential election may not depend on who wins the Buckeye State's 20 electoral votes.

Still, election experts say that with an Ohio Supreme Court case pending that could delay the counting of some absentee ballots, plus possible legal challenges and the potential for a large number of provisional ballots that by law aren't counted for 10 days, there's a growing chance an Ohio winner won't be declared on election night.

"That risk seems increasingly larger as the days progress," said Edward "Ned" Foley, director of Election Law @ Moritz at Ohio State University.

Those odds may be even higher for hotly contested congressional races such as the 15th District race in central Ohio, or tight legislative races that may determine which party controls the Ohio House, observers said.

But Foley and others argue that although the public and media have become conditioned to wanting a winner on election night, what's more important is that both sides have confidence in the outcome -- even if it takes awhile.

"Everybody needs to just calm down and relax," said Bradley A. Smith, a Capital University Law School professor and former Federal Election Commission member.

There was no calming down yesterday, with the election barely two weeks away. Secretary of State Jennifer Brunner said "security breaches" caused her to shut down part of her Web site, that she had received death threats and that her office had been mailed a suspicious package covered with threatening messages and containing an unidentified powder last week. The State Highway Patrol is investigating.

Meanwhile, prosecutors in at least three more Ohio counties -- Delaware, Hamilton and Hardin -- are looking into possible voter-registration fraud. And while Republicans continued to allege fraud in Ohio, Democrats accused McCain of running a dishonorable campaign and the GOP of "desperate tactics."

"It causes me to wonder, quite frankly, if there may not be an effort to set up a scenario where the Ohio outcome could be challenged," Gov. Ted Strickland said. "I think that would be terribly unfortunate if it happens."

At the heart of the current dispute is a disagreement about what should be done when personal information from newly registered voters doesn't match state motor-vehicle and federal Social Security databases.

Secretary of State Jennifer Brunner has estimated that as many as 200,000 of the 660,000 Ohioans who registered since Jan. 1 have mismatches. She thinks most are the result of typos or other legitimate discrepancies, and that Ohio's bipartisan election system has the tools to catch widespread fraud.

But Republicans sued to force Brunner to provide details about the mismatches to county elections boards as another way to correct errors and weed out fraud.

The lawsuit seeks an order that Brunner direct elections boards not to process absentee ballots unless they first are checked for voter mismatches and verified for eligibility.

Brunner tried to get the case moved to federal court yesterday on grounds it involves primarily a dispute over what federal law requires, but U.S. District Court Judge George C. Smith sent it back to the seven Ohio justices.

Lt. Gov. Lee Fisher has called for four of the justices who have financial ties to the GOP fundraiser who filed the lawsuit to remove themselves from the case. Justices Evelyn Lundberg Stratton and Maureen O'Connor, both of whom are on the ballot this fall, did so yesterday, as they have on other cases concerning the 2008 election. Justices Terrence O'Donnell and Robert R. Cupp have not.

Democrats are accusing Republicans of a coordinated effort through lawsuits and investigations of trying to intimidate new voters from casting ballots and distracting voters.

They point to Hamilton County Prosecutor Joseph T. Deters, McCain's southwestern Ohio chairman, who subpoenaed certain unredacted voter-registration records from that county.

Deters removed himself from the investigation yesterday and a Hamilton County judge reportedly appointed Mike O'Neill, a former assistant county prosecutor, as a special prosecutor to head the investigation.

But Robert F. Bauer, general counsel for the Obama campaign, argued during a conference call that conducting investigations before an election is designed to "chill" legitimate voting.

Republicans said they're trying to protect the integrity of the vote and defended McCain.

"It is not negative campaigning to call Barack Obama out on his partisan record, his failed judgment, or his questionable associations," said Paul Lindsay, McCain's Ohio spokesman.

Delaware County Prosecutor David Yost said his office is looking into two cases of potential voter-registration fraud that were referred to him by the board of elections.

One includes "a handful" of people whose registration confirmation cards were returned to the elections board because they were undeliverable.

The second involves a family of five, all of whom wrote on their registration cards that they were born on Jan. 1 but in different years.

The prosecutor's office in Hardin County, about an hour northwest of Columbus, also is investigating possible registration fraud. No other information was available.

Dispatch staff reporter Jill Riepenhoff contributed to this story.

mniquette@dispatch.com