CINCINNATI -- History says a loss in Ohio would deal a deathblow to Mitt Romney's presidential prospects, but a potential Buckeye State defeat might not end the Republican's chances on Election Day, analysts said.

With a diverse mix of urban enclaves and rural communities, Ohio is the closest thing to a true bellwether in presidential politics. And Romney, in the largest rally of his presidential campaign, told supporters here, "This is the one we have to win."

Yet, some election forecasters were hesitant to label this state as the inevitable annointer of the next president.

"When it comes to Ohio, we can't be too enslaved to history," Nathan Gonzales, deputy editor of the Rothenberg Political Report, said. "It's true that no Republican has won the presidency without Ohio. But until four years ago, we had never had an African-American elected president. I hope we've all learned that just because something hasn't happened before, that we don't think it can't or won't ever happen."

But Gonzales added that without Ohio, Romney has a narrow, difficult road to the White House .

"He either has to win virtually all of the remaining swing states or win one of the late-breaking opportunities such as Pennsylvania or Michigan," Gonzales said. "Both paths are possible, just difficult to pull off."

A couple of factors make Ohio unique. President Obama's championing of the auto bailout is a clear advantage here, where one in eight jobs are tied to the industry. Also bolstering the president's re-election hopes, the Ohio economy has recovered at a much faster pace than those of other battleground states.

This much is certain: Ohio is more expendable for Obama than Romney, as the president has a wider assortment of combinations that could realistically put him above the magical threshold of 270 Electoral College votes.

Or as one top GOP strategist told The Washington Examiner, "If Romney loses Ohio, we better hope that a whole lot of polls in a whole lot of other places are dead wrong."

The president will spend his final day on the campaign trail in Iowa, Wisconsin and Ohio, attempting to buttress his Midwestern firewall. Romney has invested more time and resources in blue states of late. Polls have shown the race tightening in Pennsylvania and Michigan, states that have been reliably Democratic for decades. But those states are still considered a long shot for Romney.

A breakthrough in one of those Democratic bastions could offset the loss of Ohio for Romney. If that didn't happen, and Ohio slips away, Romney would probably have to win at least three of four other states rated as tossups, or within the margin of error in polls: New Hampshire, Wisconsin, Iowa and Colorado.

That is a much tougher path than pulling out the Buckeye State.

Despite a string of recent polls that give Obama a slight lead in Ohio, the Romney campaign insists they'll prevail on Election Day, saying they have offset the edge Obama was expecting from early voting here. They also point out that Romney is besting Obama among Ohio independent voters, who they believe will crown the winner in this state.

One of Ohio's most reliable pollsters on Sunday said the race remained too close to call. The final Columbus Dispatch poll shows Obama leading Romney 50 percent to 48 percent, within the survey's margin of error.