David Carr NYT column: ‘In the last few days, conservatives have become agitated about Mitt Romney’s drop-off in the polls. So did they think the stumble was because of the ill-fated “47 percent” slip of the lip, or the hasty effort to gain a political edge after the death of an American ambassador in Libya, or more problematically, a campaign that can’t seem to stop pratfalling no matter what the news?  No, in their view, the mysterious drop can only be explained by the fact that the mainstream media have their collective liberal thumb on the scale, in terms of coverage and, more oddly, polling.’