Three weeks before Election Day, Republican leaders in Ohio have asked the Supreme Court to step in and allow the state's early in-person voting restriction to take effect.

Two lower federal courts have ruled in favor of Obama campaign officials who asked for a preliminary injunction against Ohio's law, which allows only military members and their families to vote in person on the three days prior to the election.

The Obama campaign, joined by state Democratic Party officials, had challenged the law, pointing out that all voters had been allowed to vote in that time frame in recent elections.

A three-judge panel of the Sixth Circuit Court of Appeals sided with the Democrats Oct. 5 and said that if local election boards in Ohio allowed early voting from Saturday, Nov. 3 to Monday, Nov. 5, the voting had to be open to all voters.

"The state must show that its decision to reduce the early voting time for non-military voters is justified by a 'sufficiently weighty' interest," the court said. "The state has proposed no interest which would justify reducing the opportunity to vote by a considerable segment of the voting population."

The legal dispute comes in a state of critical importance for the upcoming presidential election.

Edward B. Foley, an election law expert at the Ohio State University Moritz College of Law, says, "the Obama campaign's concern is that there is a federal constitutional violation by giving voting opportunities to military voters that are not extended to all eligible voters. The campaign is suing under the Equal Protection Clause of the Constitution, which has a long track record in the U.S. Supreme Court in applying to voting laws."

In the emergency application, filed with Justice Elena Kagan, who has jurisdiction over Ohio's 6th Circuit Court of Appeals, Ohio's Attorney General Michael DeWine and Secretary of State Jon A. Husted say the lower court got it wrong.

"Based on nothing more than supposition the Sixth Circuit held that this modest reduction of in-person absentee voting disenfranchised thousands of voters, even though any voter who had previously used this three-day period to vote in person still had access to 230 hours of in-person absentee voting, more than 750 hours of absentee voting by mail, and 13 hours of voting on Election day," they say.

In court papers, the Ohio officials say the law was changed partly to reduce the burden on election officials and give them enough time to prepare for Election Day. They say that the courts are interfering with the state's administration of elections.

"At bottom, the Constitution allocates to the states the responsibility to run elections," they say. "Enjoining state election laws as facially unconstitutional, especially right before an election, frustrates the framers' design and disrupts election administration in multiple ways."

But Robert F. Bauer, a lawyer for the Obama campaign, argues that the Ohio system is unique.

"Nowhere else in the country will an eligible voter be turned away from a single, open polling place because the polling place is open for some voters, but not for that particular voter," he writes in court papers.

Bauer urges the court to deny Ohio's request and allow the preliminary injunction against the law to remain in effect. He argues that about 100,000 voters cast in-person ballots in the three days leading up to Election Day in 2008.

"Although the legal issues are tricky, at bottom all sides are also concerned with the political implications," says Joshua A. Douglas, a professor of law at the University of Kentucky College of Law. "The Obama campaign is obviously concerned that some of its most reliable voters plan to use the last few days before Election Day to head to the polls. Republicans have similar concerns, but just for their set of voters.

"An underlying concern for the court will be rendering a timely decision. The worst case is local election officials not knowing the rules as Election Day approaches," Douglas said.

Republican attorneys general from 15 states have filed a brief in support of Ohio, arguing that the lower court decision in the case "impinges" on state sovereignty.