The Guardian writes:

The lying from the Romney campaign is so out-of-control that Steve Benen, a blogger and producer for the Rachel Maddow show compiles a weekly list of “Mitt’s Mendacity” that is chockfull of new untruths. Benen appears unlikely to run out of material any time soon, particularly since Romney persists in repeating the same lies over and over, even after they’ve been debunked.

This is perhaps the most interesting and disturbing element of Romney’s tireless obfuscation: that even when corrected, it has little impact on the presumptive GOP nominee’s behavior. This is happening at a time when fact-checking operations in major media outlets have increased significantly, yet that appears to have no effect on the Romney campaign.

Why does this keep happening?

Romney has figured out a loophole – one can lie over and over, and those lies quickly become part of the political narrative, practically immune to “fact-checking”. Ironically, the more Romney lies, the harder it then becomes to correct the record. Even if an enterprising reporter can knock down two or three falsehoods, there are still so many more that slip past.