More than $39 million has been spent on television ads in Ohio by the two presidential candidates and their affiliated outside groups as of early July, according to data provided to the Fix by a Republican media buying firm, a massive outlay of campaign cash that re-affirms the centrality of the Buckeye State in the electoral calculus of both parties.

U.S. President Barack Obama greets residents of Beaver, Ohio July 6, 2012. Obama is on a two-day campaign bus tour of Ohio and Pennsylvania. REUTERS/Kevin Lamarque

And a panoply of outside groups — largely clumped on the conservative side — have dumped millions more into Ohio.

Crossroads GPS, the 501(c)(4) arm of American Crossroads, has spent $3.1 million on ads in Ohio (and that’s before the $25 million expenditure the group announced Friday morning). Americans for Prosperity, the Koch brothers group, has spent $1.8 million on ads in Ohio as has Restore Our Future, a super PAC run by former Romney aides.

On the Democratic side, the biggest outside spender on ads in Ohio is Priorities USA Action, a super PAC run by former White House aides. Priorities has spent $2.8 million in the Buckeye State.

Not surprisingly, the ads, which have been mostly negative in tone, have left many Ohio voters sick of the election — with more than four months still to go.

“I don’t even try to pay attention to that stuff because it’s all just dirty politics,” said Tanya Schlabach, a single mom in Canton, Ohio. Added Bill Corley of Westlake, Ohio: “All I hear is Obama’s negative campaigning… I don’t hear enough positive about Romney. I just hear all the negative from the Obama campaign.”

While TV ad spending isn’t the sole indicator of the electoral importance of a state, campaigns aren’t in the habit of spending money — especially tens of millions of dollars — on non-competitive states.

Given that, here’s a look at the five states where Obama and Romney have spent the most on ads as of July 3.

Obama: 1. Ohio ($22 million) 2. Florida ($17 million) 3. Virginia ($11.4 million) 4. North Carolina ($10.9 million) 5. Iowa ($8.5 million)

Romney: 1. Ohio ($6.4 million) 2. North Carolina ($4.7 million) 3. Virginia ($2.8 million) 4. Colorado ($2.7 million) 5. Iowa ($2.7 million)

Ohio, Virginia, North Carolina and Iowa make both lists. Colorado, which ranks fourth in spending for Romney, is sixth ($7.9 million) for Obama. Romney has spent just over $2 million in Florida but Crossroads GPS has dropped over $5 million on ads in the Sunshine State while Restore Our Future has spent $2.4 million there.

Among the “swing” states where relatively little is being spent on ads includes Michigan (NO spending by either campaign), Wisconsin (NO spending by either campaign) and Pennsylvania ($5 million by Obama, zero by Romney).