Updated: 5:55 p.m. ET
COLUMBUS, Ohio -- The Supreme Court on Tuesday cleared the way for voters in the battleground state of Ohio to cast ballots on the three days before Election Day, giving Democrats and President Obama's campaign a victory three weeks before the election.
The court refused a request by the state's Republican elections chief and attorney general to get involved in a battle over early voting.
Ohio is among 34 states, plus the District of Columbia, where people can vote early without giving any reason. About 30 percent of the swing state's total vote -- or roughly 1.7 million ballots -- came in before Election Day in 2008. Crucial to Obama's win that year was early voting in Ohio, North Carolina and Florida.
Obama won Ohio four years ago, but Republican rival Mitt Romney is making a strong play for it this year. No GOP candidate has won the White House without Ohio in his column.
Obama's campaign and Ohio Democrats had sued state officials over changes in state law that took away the three days of voting for most people but made exceptions for military personnel and Ohioans living overseas.
Their lawsuit cited a recent study saying nearly 105,000 people voted in the three days before the election in 2008, and they argued everyone should have the chance to vote on those days. They also said eliminating the opportunity for most Ohio residents to vote in person on those days, while giving military or overseas voters the chance to do so, leads to unequal treatment.
Attorneys for the state said many laws already grant military personnel special voting accommodations, such as requirements for states to send absentee ballots to them 45 days before the election. And they argued local boards also need those final days to prepare for the election.
On Oct. 5, a federal appeals court reinstated voting on the weekend and Monday before the election and returned discretion to set hours on those days to local boards of elections.
Ohio Secretary of State Jon Husted appealed that ruling to the Supreme Court last week. He said it opened up the chance for Ohio's 88 county boards of elections to set different rules, while simultaneously ordering that all voters be treated the same.
But the high court allowed the lower court's ruling to stand.
Before the changes to the Ohio law, local boards of elections set their own early voting hours. And those hours varied among the state's counties.
Husted had been accepting boards' recommendations for hours on the disputed days in the event his appeal wasn't successful.
About an hour after the high court's decision, Husted ordered uniform hours across the state. The hours are from 8 a.m. to 2 p.m. on Saturday, Nov. 3; from 1 p.m. to 5 p.m. on Sunday, Nov. 4; and from 8 a.m. to 2 p.m. on Monday, Nov. 5.
Husted said that despite the high court's ruling, he believes the Ohio Legislature, not the federal courts, should set the voting rules.
"However, the time has come to set aside the issue for this election," he said in a statement.
Husted said the new statewide hours on the three days will give Ohioans the same opportunities to vote regardless of their home county.
Bob Bauer, general counsel for Obama for America, praised the Supreme Court's decision.
"We now turn our full attention to educating Ohio voters on when and how they can vote along with presenting the clear choice they face when selecting their next president," Bauer said in a statement.