Others have touched on this already, but it really deserves highlighting here, too. Check this out, from the new NBC/WSJ poll:

Barack Obama recently said that if you have been successful, you did not get there on your own. There was a great teacher somewhere in your life. Somebody helped to create the American system that allowed you to thrive. He said if you have a business, you didn’t build that, somebody else made that happen. When we succeed, we succeed because of our individual initiative, but also because we do things together. Does this make you feel more positive or more negative about Barack Obama, does it not make much difference in your opinion or do you not know enough about this to have an opinion at this time?

More positive: 36

More negative: 32

Not much difference: 26

Romney built much of his convention around Obama’s “you didn’t build that” comments, but only 32 percent were impacted negatively by them. Meanwhile, more viewed the remarks as a positive, and 62 percent either saw them as a positive or weren’t impacted by them at all.

The poll also asked people how Romney’s remarks about the freeloading 47 percent affected their views of the GOP candidate. The result: 23 percent said “more positive”; 24 percent said “not much difference”; and 45 percent said “more negative.”

The freeloading 47 percent video was far worse for Romney than “you didn’t build that” was for Obama. Now, it’s important to be careful about these numbers. Often controversies over remarks like these have an impact on public perceptions of candidates’ images in unseen ways. While people say they don’t care about such remarks — just as high numbers say they don’t see Romney’s Bain years as a negative — this stuff can end up reinforcing underlying views of candidates, anyway. The better way to judge whether such efforts to define the opposition are working is to look at public perceptions of the target’s overall image and policy priorities.

And on that score, it’s clear who is winning the definition battle. Poll after poll after poll shows people think Romney doesn’t care about the needs and problems of ordinary Americans, and that his policies are skewed to favor the rich. Cementing those perceptions was the real strategic goal of the Obama camp’s attacks on the freeloading 47 percent remarks, on Romney’s low tax rates and web of offshore dealings, and on Bain layoffs and offshoring. Meanwhile, poll after poll after poll shows people still think Obama cares more about the needs and problems of folks like them and that he can be trusted to look out for the middle class. This, even though the “you didn’t build that” attacks were designed to persuade struggling Americans that Obama disdains people’s hard work and doesn’t really sympathize with their plight.

How to explain this? As Benjy Sarlin notes, GOP focus grouping reveals swing voters simply don’t believe that GOP attacks on this or that Obama quote truly reflect what he really thinks. But they’re inclined to accept that Dem attacks on Romney quotes do reflect his true beliefs.

Why? My best guess is that the GOP attacks have been rooted in an inability to understand how swing voters really view Obama — they have been attacking an Obama that doesn’t really exist outside the GOP base’s imagination. So there’s no soil there for these attacks to take root. Meanwhile, the summer attacks on Bain told a story about Romney that people were prepared to accept, given who Romney really is, and more recently, the 47 percent remarks further reinforced already hardening perceptions of Romney’s real beliefs and policy priorities.

All of this might not be enough to guarantee an Obama victory; Romney could still win, based on the economy. But if Romney loses, all of this will help explain a lot.