Give credit to Carney on this one: He doesn’t even try to engage the question. What could he possibly say? Sometimes discretion really is the better part of valor, my friends.

And yet, if you believe pollster Mark Blumenthal, the negativity hasn’t hurt O. Yet.

Has this advertising had an impact? If we compile all the individual ratings across all the national polls into HuffPost Pollster trend charts, the recent changes appear to be glacial at best.

For Romney, the chart shows a significant increase in his unfavorable rating during the Republican primary campaign, but since April that rating has remained mostly unchanged. His favorable rating did jump significantly in March and April as he became the presumptive nominee of the Republican Party. Analyses by individual pollsters concluded that most of that gain came from Republicans.

For Obama, the trend lines have moved even less, with his positive and negative ratings remaining mostly flat throughout 2012. The HuffPost Pollster chart does indicate a roughly one-point drop in Obama’s favorable rating and a roughly one-point increase in his unfavorable rating over the past month.

I thought his Bain attacks on Romney would end up driving Obama’s numbers down, but either I gave him too much credit for likability or not enough. Barring something extraordinary happening, it looks like his popularity isn’t going to move much from now until November. What does that mean for Mitt’s ad strategy going forward?