Challengers hovering inside polling places could intimidate voters and worse, they said.

"I would not be surprised to see arguments and maybe a little sporadic fisticuffs," Democratic state Rep. Tyrone Yates said after testifying that their presence could make black voters confused and angry.

Also Thursday, the U.S. Department of Justice announced it will send monitors to Hamilton County on Election Day to make sure voters' civil rights are not violated. Cuyahoga and Franklin are also among the 86 jurisdictions in 25 states where federal monitors will be sent.

In the lawsuit, civil-rights activists Marian and Donald Spencer of Avondale claim the state law permitting challengers is a vestige of Jim Crow laws that aimed to disenfranchise black voters.

One of two election-related cases pending before U.S. District Judge Susan Dlott, the suit requests a temporary restraining order barring challengers.

"We don't want the kind of disaster here that we had in Florida," Donald Spencer said. "We see this as a terrible thing for us in the North to have. We're very concerned."

The case was filed against the Hamilton County Board of Elections, Ohio Secretary of State Kenneth Blackwell and Hamilton County GOP Chairman Michael Barrett.

Republicans say the challengers will attempt to prevent voter fraud, not to block legitimate voters.

In almost three hours of testimony, Hamilton County Democratic co-chairman Tim Burke raised concerns that Republicans are targeting black voters and that the rules for how to handle challenges are murky.

"I am concerned that having many challengers in polling places next Tuesday will slow the election, perhaps dramatically, and may ... intimidate voters when they are faced with a situation they've never seen before at their polling place," he said.

Republicans have named challengers to 629 county precincts and Democrats to 557 precincts, according to Burke, who is also chairman of the Board of Elections.

Both parties listed their precinct executives as challengers in their respective precincts, he said, but Republicans also submitted a list of 251 other precincts where they may put challengers.

Of those 251, Burke said, 250 are majority-black precincts. Republicans put a challenger in a Madisonville precinct, for instance, but not in an Oakley precinct nearby. There are 1,013 precincts in the county.

Barrett said after the hearing that, while he was not involved in assigning challengers, it appears the Republicans targeted precincts with a lot of new voters.

The GOP says it is concerned about fraudulent voter registrations, targeting some 5,000 newly registered voters in Hamilton County whose mail has been returned as undeliverable.

They are predominately in Democratic - and black - precincts because so many of the new voters were registered by Democratic-affiliated groups.

"I think it's the Democrats trying to divide the community and create two Hamilton Counties," Barrett said of the lawsuit.

Burke and lawyers for the Spencers also raised questions Thursday about the Board of Elections' procedures for handling challenges.

Challengers have long been permitted in Ohio but this is the first time the parties are expected to take advantage of the law and many of the rules are untested.

Attorney Jennifer Branch painted a hypothetical picture of a woman who, upon being challenged, says she "stays with her mom." She's been there for two months and isn't sure how long she'll remain. Does she "reside" there? Who decides, the presiding judge or all four precinct judges? Will the judges know how to handle the question?

"We are doing the best under the circumstances that we can" to make sure poll workers know what to do, Board of Elections Director John Williams said after the hearing. "It does cause me some concern."

Blackwell's office is issuing new instructions virtually daily in an effort to clarify such issues.

E-mail candrews@enquirer.com