The new Pew poll finds that Obama leads Mitt Romney among registered voters nationally by 50 to 43. But the more interesting finding may be that there’s been a big swing against Romney on the economy in particular:

The job situation remains the number-one issue for voters in this campaign. Neither candidate has a clear advantage on this issue: 46% say Romney and 42% say Obama can do a better job improving the job situation.

More generally, Mitt Romney has lost ground over the past month on the issue of the economy. The eight-point advantage he held in June as the candidate better able to improve the economy has now flipped, with 48% saying Obama can better improve economic conditions, while 42% favor Romney.

Last month, Romney held an eight point advantage on who can best improve the economy; now Obama holds a six point advantage. Among independents, there’s also been a big swing.

In June, Romney led Obama by 23 points, 54-31, among independents on the economy. That lead has dwindled down to four points; Romney now leads among them on the issue by 43-39.

And this is even more interesting: The swing on the economy has been bigger in the dozen battleground states than it has been nationally, though the difference is within the margin of error.

Pew sends over some numbers: In June, Romney led Obama in those dozen states by eight points on the economy, 49-41. Now Obama leads Romney in those same states by nine points, 50-41. Interestingly, there’s been no shift in the horse race numbers in those states — Obama leads 51-44, similar to last month — but clearly, Romney has lost real ground on the economy in them, even though he has been relentlessly pounding Obama’s economic stewardship as a disastrous failure.

What’s more, this comes as voters remain sour on the economy — 51 percent say they are hearing mostly bad news about jobs — yet Obama seems to be neutralizing or even reversing Romney’s previous advantage on the issue anyway, at least in this poll.

With the usual caveat that you don’t want to read too much into one survey, it’s worth asking whether the swing on the economy may be partly due to the Bain attacks. Though pundits mostly think these attacks are about nothing more than painting Romney as a heartless plutocrat, in reality they are also about directly engaging, and relentlessly undermining, Romney’s central argument for the presidency, i.e., that his business background has equipped him with job creation skills that will enable him to turn around the country’s economy. Romney’s slippage on the economy in this poll may be another sign that the attacks are working. At the very least they will certainly embolden the Obama camp to keep them up.