Voters in this crucial swing state began casting absentee ballots Tuesday, after state and federal courts upheld a ruling that allows residents to register and vote absentee on the same day during the first six days of voting.

Five people were waiting at the Cuyahoga County Board of Elections when doors opened at 8:30 a.m. Two in line said they were voting for Democratic presidential candidate Barack Obama, including John Fuller, 73, a retired hospital orderly from Cleveland.

Fuller said voting early would allow him to work on Election Day helping others get out and vote. Fuller and others in line Tuesday morning were previously registered.

Election officials around Ohio prepared for a rush of early voting Tuesday, the first day absentee ballots are accepted in advance of the Nov. 4 presidential election.

Backed by the state Supreme Court and two federal judges, Secretary of State Jennifer Brunner, a Democrat, is allowing new voters to register and cast an absentee ballot on the same day from Tuesday through Oct. 6.

For weeks, the Ohio Republican Party accused Brunner of interpreting the early voting law to benefit her own party by allowing same-day registering and voting. Republicans argued that Ohio law requires voters to be registered for 30 days before they cast an absentee ballot.

But the Republican-dominated Ohio Supreme Court decided Monday that Brunner was following the law. The decision was backed by a federal judge in Cleveland. Another federal judge in Columbus declined to rule, deferring to the state Supreme Court's decision.

On Tuesday, the Ohio Republican Party asked the 6th U.S. Circuit Court of Appeals in Cincinnati should either stop same-day voting or at least require the state's top elections official to separate those ballots so they can be verified. Brunner, however, has already instructed election officials to segregate the ballots cast by those who register on the same day and verify the registration information before those ballots are counted.

The second voter in line at the Board of Elections here was Julia Kramer, 19, a Case Western Reserve University freshman from New York City and an Obama volunteer. She said she's been working on campus to register out-of-state students to change their registrations to Ohio because of its critical role in the election.

Nevertheless, "A lot of people are really attached to their hometowns," Kramer said. "It's hard to explain to people that your vote (in New York) won't count as much."

In Columbus, voters wanting to cast ballots as soon as possible on Tuesday morning had set up tents Monday night to wait in line outside the Franklin County Board of Elections.

Obama's campaign organized car pools from college campuses to early voting sites. The Northeast Ohio Coalition for the Homeless is ferrying voters from homeless shelters to polling sites in the Cleveland area. Other organizations that seek to increase poor and minority participation in elections are transporting voters from low-income neighborhoods.

The targeted voters have all traditionally had a harder time getting registered, and then getting to polling places on Election Day.

Republicans weren't ceding the early voting crowd just because they were engaged in a court challenge.

"You have a special opportunity to help elect John McCain, Sarah Palin and Republicans across the ballot," a page on the Republican National Committee's Web site said.

The window occurs because state law requires absentee voting to begin 35 days before Election Day, on Sept. 30, while the end of registration for this election is Oct. 6. The window was used by voters sparingly in previous elections, but never got any attention until the Republican-controlled Legislature passed a law in 2005 that enabled all Ohio voters to vote absentee.