It probably won't move the polls much:
Unless the Romney campaign has a fundamentally new pitch, it’s hard to see why voters that have already heard these advertisements will now suddenly find them persuasive.
The fact that Team Romney is poised to spend even more money doesn’t undermine this analysis. GOP-aligned Super PACs aired uncontested advertisements in Michigan, eastern Pennsylvania, Wisconsin, Minnesota, and New Mexico, but only Wisconsin moved into the toss-up column after Paul Ryan was selected as Romney’s running mate. The Republican National Convention could be reinterpreted as a three hour, nationally televised infomercial, and yet Romney didn’t receive any bounce at all. And while the science of ad spending is somewhat unscientific, there is probably a point of diminishing returns, even if the exact slope of the diminishing curve is uncertain.
My sense is that Charlotte reminded a lot of people what they have gone through with this president, and why they continue to like him, outside the hater groups on the right. They still don't see him finding a miracle to end the economic torpor, and they're pissed about that – but nothing Romney has proposed (such as it is) is more appealing to them.
I think sliming Obama personally could actually help the president. I also think Romney should have stuck to a simple "Obama's not working" line, and picked a running mate to reflect that. And stuck with it. Instead, we've had two strategies – a base one, with Ryan and Robertson and Steve King and Sheldon Adelson, and a centrist one, with, er, Ann. The national security card has been taken from Mitt, as have most of the social issues. What they Republicans have left is a debt reduction plan that would explode the debt or tax the middle classes far more than currently, and a minority base whose real passion – hatred of the president – is simply not widely shared among undecideds. The contradictions multiply, like Randian Catholics.