CLEVELAND – A jubilant Hillary Clinton exulted Tuesday night that “as Ohio goes, so goes the nation.”

Celebrating her decisive Democratic primary win in what’s arguably the most important swing state in the nation, Clinton repeated the given wisdom: No Republican has ever been elected president without winning Ohio. JFK was the last Democrat to win without the Buckeye State.

Yet was Clinton’s lopsided Ohio victory – defeating Barack Obama in virtually every part of the state and in 83 of 88 counties – a harbinger of November?

Or are the factors that combined to put her over the top – the white, rural vote; trade; the return of more conservative, blue-collar Reagan Democrats to the Democratic fold; and national security – more likely to swing Republican John McCain’s way in the general election?

Four years ago, the vast swath of Southeast Ohio covering Appalachia and coal-mining country was key to George W. Bush’s 2004 presidential win in Ohio.

Yet on Tuesday, Clinton won this region by ratios as high as 3-to-1 and 4-to-1 over Obama – drawing nearly half of all registered voters to the polls in some rural counties.

Adding to that was a huge crossover vote on Tuesday.

With tens of thousands of independents and Republican voters becoming Democrats so they could vote in that party’s Ohio primary, has the pendulum in this swing state swung to blue?

The Ohio Democratic Party thinks so. It says Democrats now outnumber Republicans in Ohio by a ratio of more than 2-to-1.

In six traditionally “red” counties in central, western and southern Ohio, the state party says the combined votes for Clinton and Obama exceeded the total votes John Kerry got in November 2004, when he was the Democratic nominee.

Further, Democratic ballot requests outnumbered Republican ones in 71 counties – 65 of which President Bush carried in 2004.

Some of these crossovers were intentional spoilers – voting for Clinton because they thought she’d do worse against McCain than Obama, with his ability to draw across party lines and to bring voters to the polls who’d sat out prior elections.

Republican Eric Klieber of largely Democratic Cleveland Heights told a reporter that he’d decided to switch parties and vote for Clinton because, “John McCain has a better chance of beating her than Barack Obama.”

Yet other such switch-hitters clearly voted local preferences.

In Franklin County, home to Ohio State University and the state capital, Columbus’ mayor strongly backed Obama. The Illinois senator won, thanks to 69 percent of voters who cast Democratic ballots.

Yet only 7 percent of Franklin County voters are registered Democrats, according to the county Board of Elections.

In Brown County, nudging Appalachia and a traditionally “red-voting” county, Clinton won by a 3-to-1 margin – thanks to the six of every 10 voters who asked for a Democratic ballot.

That in a county with only 12 percent registered Democratic voters, according to the Brown County Board of Elections.

Yet Brown County’s nearly 47 percent turnout Tuesday, although high by state standards, was nowhere near its 70 percent turnout for Bush’s re-election. Bush’s ability to draw suburban, downstate and rural Republicans to the polls in 2004 was the key to victory in Ohio.

Still, there’s no minimizing the boost Clinton gets from an Ohio win among constituencies important for victory in November, including union workers, older women, white men and rural voters focused both on the economy and on Iraq.

Nor is there any nice way to avoid the conclusion that were Obama to be the Democratic nominee, he would be hard-pressed to win Ohio, if only because he is an African-American.

Clinton’s lopsided win in rural Ohio was no fluke: Few states’ voters in this primary season have shown so baldly the urban-rural divide in their willingness to embrace a black man for president. It’s not nice, justifiable or wise, so it may be that Ohio voters will think differently in November. Or maybe not. That’s one of the gambles with a swing state.

Elizabeth Sullivan is foreign affairs columnist and an associate editor of the editorial pages for The Plain Dealer of Cleveland. She can be contacted at bsullivan(at)plaind.com.