Correction: This article has been corrected to reflect that a poll previously described as a joint Washington Post/ABC News poll was conducted solely by The Washington Post.

In the four months since Mitt Romney clinched the GOP presidential nomination, about 20 nonpartisan polls have been taken in the battleground state of Ohio. Romney has led President Obama in just three of them.

The latest bad news for Romney and his running mate, Rep. Paul Ryan, came Wednesday, when a new Quinnipiac University/New York Times/CBS News survey showed Obama opening up a double-digit lead over his rival, taking 53 percent among the state’s likely voters to Romney’s 43 percent.

That’s an even wider margin than in Tuesday’s Washington Post poll, which showed Obama taking 52 percent to Romney’s 44 percent among Ohio’s likely voters.

Why has the Buckeye State so eluded Romney in his bid for the White House?

Part of the trouble for Romney is that Obama has showered the state with money and attention over his nearly four years in office. The president’s visit to Bowling Green and Kent on Wednesday marked his 13th trip to the state this year and his 29th since taking office, and either Obama or Biden has visited Ohio an average of once every three weeks since they were inaugurated in 2009.

Romney, who was wrapping up a two-day bus tour in the state Wednesday, has visited Ohio 17 times during the 2012 cycle, including 10 trips since May, according to his campaign. Ryan (Wis.) has headlined more than half a dozen events in the state since being tapped last month to serve as Romney’s running mate, making it his most-visited state.

Romney has also been overshadowed by Obama when it comes to TV ad spending in the state. According to a National Journal tally, Obama’s campaign had spent nearly $41 million on TV ads in Ohio from May 1 to early September, compared with nearly $21 million for Romney.

Romney has been given a boost by a combined $21 million spent by GOP-aligned outside groups, including Crossroads GPS, Restore Our Future, American Future Fund and Americans for Prosperity, as well as an additional $2.8 million spent by the Republican National Committee. But in Ohio as in other states, it appears that the impact of that super PAC spending has fallen short of expectations.

Obama, too, has gotten a lift in Ohio in the form of nearly $7 million worth of TV ads aired by the Democratic-leaning super PAC Priorities USA Action.

The polls released this week indicate that the Obama campaign has outmaneuvered the Romney camp in terms of its get-out-the-vote operation: Thirty-six percent of registered voters in Ohio polled by The Washington Post said they had been contacted by the Obama campaign, compared with 29 percent who had been contacted by the Romney campaign. The gulf in Ohio was wider than in Virginia or Florida, the two other battleground states polled.

The new surveys show Romney at a disadvantage against Obama on several issues and among key groups of Ohio voters. Sixty-four percent of registered Ohio voters polled by The Washington Post said they viewed the federal government’s bailout of the auto industry, which Romney opposed, as “mostly good.”

Romney has also lost ground to Obama on the matter of how he would handle the economy: In Wednesday’s Quinnipiac University/New York Times/CBS News survey, 51 percent of likely Ohio voters said Obama would do a better job, compared with 45 percent who said the same of Romney; last month, the candidates were tied on the issue.

And while Obama’s favorability ratings appear to have held steady among Ohio voters, unfavorable views of Romney have ticked upward in the past four months. An NBC News/Wall Street Journal/Marist University poll released this month showed that 51 percent of registered Ohio voters have an unfavorable view of Romney, up from 47 percent in May. Obama is viewed unfavorably by 44 percent — on par with where he stood in May — and favorably by 51 percent.

Ohio is not the only swing state in which polls have consistently shown Romney at a disadvantage, although with 18 Electoral College votes, it is one of the largest. In New Hampshire and Nevada, Romney has not led Obama in a single nonpartisan poll since winning the GOP nod. In Virginia and Colorado, Romney has led in just a handful.

Romney’s camp has downplayed its deficit in public polls; the campaign’s national political director, Rich Beeson, told reporters Tuesday that “the ground game is good for a field goal” and that “if you’re within three points, it can make a difference.”

Even so, with early voting in Ohio set to begin Oct. 2, the Romney-Ryan ticket has little time to waste in working to make up ground.