Not that they need me to advertise, but MWO has their response to Brendan Nyhan up.
Without delving too much into the substance of Nyhan's work -- others have done that (off the top of my head) -- I have a "final" comment.
Spinsanity is a good site when they research and explain factual misrepresentations (you know, lies) by politicians or others. Where they always lose me is when they attempt to Broderize politics and the media. A bit of hyperbole, harmless exaggeration, or colorful humor should not be out of bounds of legitimate political discourse. In fact, it makes it all a bit fun.
I wish there was a higher level of political discourse in this country. But the problem isn't with MWO, or even Rush Limbaugh, it's on the pages of the Post and Times, every day on MSNBC, Fox, and CNN. There is no shortage of places to get wonky discourse, but as we've all learned screaming loudly works. It doesn't just work because the masses hear it -- it works because it is the only way for outsiders to get the mainstream media to pick up and trumpet their stories.
