This, from the latest Wall Street Journal-NBC News poll, has got to cause concern at McCain campaign headquarters:

*** The negative turn: It's also worth pointing out that McCain's negatives have increased as he's gone on the attack against Obama. In March, his fav/unfav was 49%-27%; now it's 43%-39% (+4). By comparison, Obama has gone from 51%-28% in March to 52%-35% (+17). In addition, Obama's numbers among independents have shot up in the latest NBC/WSJ poll: Two weeks ago, McCain led him here, 51%-38%, and now it's Obama up four, 42%-38%. All this highlights a big problem for McCain: It's increasingly harder for him to go negative, even though he's now embarked on that path. And it might be hard for him to go negative at tonight's debate given its town hall format. McCain's tone and body language tonight might be more important than anything he says. It's a tough position McCain finds himself in: On one hand, the temptation to make Obama unelectable and drive home that point is going to be great tonight. But if McCain does it in a way that makes it easy for Obama to paint him as out of touch on the economy, he could have a hard time closing the gap. That said, what if McCain finds a big econ issue that paints Obama in a corner and forces a big idea debate on McCain's turf? That would be the ideal solution for McCain, the problem is finding that issue...The 90-minute debate begins at 9:00 pm ET from here at Belmont University. It's moderated by NBC's Tom Brokaw.

John McCain goes overwhelmingly negative, and his numbers drop precipitously -- a net negative of 18 points, in fact -- while the target of McCain's mudslinging, Barack Obama, sees his numbers move significantly less, just 6 points in the negative direction. What's more, while Obama's favorable number is above 50 percent, and his net favorable number of +17 is remarkably good for someone who has sustained such strident attacks, McCain is dangerously close to the point at which more voters view him unfavorably than favorably, with just a +4 net favorable rating.

This all brings up a difficult situation for McCain. On one hand, the sustained attack that it has leveled against Obama has not only not been a success, it has actually been a net negative, so there might be an inclination to call it off and rejigger strategy. The problem with such a move is that seldom is a candidate with such lower favorable ratings able to defeat a candidate with such higher favorable ratings, particularly in an open-seat election, particularly when the political environment is so troublesome for that candidate's party. McCain's only hope at this point is to bring Obama's numbers down closer to his own. And the only way to do this is to continue to go negative, a strategy that has been backfiring. A doozy of a pickle, no?