For Ohio natives, November 4 is not only a chance to help choose who will be U.S. president for the next four years, but also a day of decision-making on casinos.

Issue 6 is a proposed amendment to the state's constitution that would allow a single non-Indian casino resort costing $600 million to be built by Blue Water Joint Venture LLC in the town of Wilmington, 65 miles (105km) south-west of the state capital Columbus.

The motion does not allow or block Native Americans from opening their own casinos, a right already enshrined in law.

But critics have expressed concern that a spate of Indian casinos could be built if Issue 6 is passed, pointing out that the amendment  authorizes for the new casino to provide more than just the bingo and lottery-style games already permitted.

Senator George Voinovich (R-Ohio), a longtime opponent gambling, is one of those critics.

"Ohio doesn't allow table games, but Issue 6 would change that, giving (tribes) half of what they need to open up other casinos if they win their land claims," Voinovich said.

A recent poll by the Columbus Dispatch found that Ohio voters favor the amendment by a clear nine-point margin.

Meanwhile, a group of developers backing the bid, called MyOhioNow.com, are suing their opponents, accusing them of running false ads against the motion.

The group wants monetary damages against an anti-gambling committee called "No on 6", claiming their ads falsely state that Ohio would lose hundreds of millions of dollars in casino profits each year because it would owner by an interstate company.