To the best of my knowledge, nobody is claiming that the ad was fair, and the story it told was misleading. But the problem for Republicans is that if you respond to the ad, you will have great difficulty not responding to its story - and that story is of the problems families face when their health insurance is tied to their employment.
So what's the solution? That's easy: you lie. You pretend not to be familiar with the details of the ad, pretend to believe that it was an official Obama campaign ad, and pretend that it says something absurd. That way you get to advance a story line of how negative the Obama campaign was, how it was detached from facts, and get to avoid responding to the difficult issues the actual ad raised.
It is simply not credible that right-wing power players are unfamiliar with the ad. It went viral, it was discussed at length (often with breathless overstatement) in political blogs, on "fact checking" sites, in editorials, on television.... The distortion is deliberate.
The Republicans have become very good at shaping a message, pushing it out through multiple channels, and sticking to the script. So it was no surprise when I heard essentially the same story being pushed again, by none other than Grover Norquist:
Norquist: [Obama] has a very expansive vision and a very different sales pitch. Eighty-six percent of his ads this year were trashing Mitt Romney as a person. He'll give you cancer. He'll do all this other stuff. Eighty-six percent...Norquist not only repeats the same essential lie about the ad and its content, he mixes in his home-brewed statistics, as if he wants to personify the phrase, "lies, damn lies, and statistics".
Rehm: I don't think he said that.
Norquist: Oh, one of the ads that was paid for on his behalf said that some guy who worked at one point for one of his firms got cancer and that was somehow Romney's fault. I don't know why they put it in the ad if it wasn't Romney's fault. That said, they went after him personally, 86 percent of the ads. He won a smashing mandate, overwhelming mandate not to be Mitt Romney. He did not run ads saying I want to spend $1.6 trillion and higher taxes.
When you see Norquist speak, he sometimes displays an odd affect that can distract you from what he's saying. But when you listen to him it's clear that he's focused like a laser on his agenda (nominally the prevention of tax increases, but more accurately the advancement of policies that shift the tax burden from the wealthy onto the rest of us).
When Norquist gets a fact wrong, rest assured, it's not an accident.