Three weeks ago, President Obama was in very good shape in swing states. He led or was tied in 9 of the 11 battlegrounds according to RealClearPolitics.

Today it appears that Mitt Romney is gaining the upper hand in several crucial states while closing in on the president in states that appeared safe for him at one time.

Mark Halperin on what is eating at Democrats on the day of the second presidential debate:

Here’s why some Democrats are worried tonight. If Romney wins the three Southern battlegrounds (FL, NC, and VA) and OH, he is at 266 electoral votes. Leaving the other five battlegrounds unallocated, that means Obama would be at 237 and Romney would only need to win one of the remaining five states to get to 270+. See the map above.

One senior Democratic official expressed real concern tonight unlike I have heard before about Ohio potentially slipping away from Obama (the state has been trending Republican in statewide races, Rob Portman has become a force, religious and gun groups are flooding the state with voter contacts, two of Romney’s top strategists have recently won a statewide race there, etc).

This doesn’t mean Romney has the upper hand right now. But it is no longer at all implausible that he could take the three Southern battlegrounds and Ohio. If he does that, he sure as heck would have the upper hand. And that leaves at least some Democrats with the shakes.

Romney is virtually even in VA and OH and ahead in North Carolina. Elsewhere, Romney is surging “near landslide” proportions in rural battleground counties:

The random cellphone and land line poll of 600 likely rural voters in nine battleground states Oct. 9-11 has Romney at 59 percent among the survey’s respondents. Obama’s support is now down to 37 percent among rural battleground voters, a plunge of 10 points from the actual rural vote in those states four years ago.

“What Republican candidates need to do is to rack up big margins in rural areas in order to offset smaller [Republican] margins in urban and suburban areas,” says Dan Judy of North Star Opinion Research, the Republican polling firm that participated in the survey.

“Mitt Romney really needs to be at 60 percent or above in [rural] areas to offset some of those [urban and suburban] margins,” Judy adds. The new survey shows “he has surged into a huge lead, and I think it is fair to say that his increased lead among rural voters is what is helping him in these swing states overall.”

And Quinnipiac’s latest Pennsylvania survey shows a huge surge for Romney among white Catholics, propelling him to within 4 points of Obama.

Bottom line: Obama still leads in the electoral college (although he is currently tied or losing the popular vote nationwide) but the trends are just awful for him. He has lost support everywhere and with just about everybody.

His goal at the debate tonight is simple: stop the bleeding. Romney, on the other hand, needs to avoid a gaffe while repeating his dynamic debate performance from Denver.

We’ll see after tonight whether the trends favoring Romney will continue no matter how well Obama does.