For example, here's Mad as Hell at Swampland:
I want the Palin-McCain lies nailed and called out for what they are, lies. Obama has to do it as the media won't do it for him.
The frustration being expressed here is that they are being allowed to get away with blatant, bald, obvious lies, and nothing seems to happen to them. Having watched a campaign where Al Gore may well have lost because he was portrayed as an elitist liar, it is extremely painful to watch these people never get called on it. So there are complaints that since the media won't do it, Obama has to call out these lies.
But that would be a mistake. When atrios says they like to piss off liberals, this is part of what is going on when they brazenly lie. They want to make you mad. They want you to get into a big fight over 300 million dollar earmarks. They want you to start shouting "Liar!! Liar!!". They want to talk about pretty much anything other than the occupation, the collapse of the housing market, unemployment, falling real wages, global warming, the deficit and health care. They want this to be about trivia and personalities. So if Obama responds in-kind, he is falling into a trap.
This is particularly true about the campaign trying to label McCain/Palin as serial liars. One of the central goals of Republican campaigns is to reinforce the idea that all politicians are alike--they all lie, they all make promises they won't keep, and they're all phonies. That's why they love negative advertising. If their opponent doesn't respond in kind, the negative image sticks. If the opponent flings mud back, then that reinforces the idea that they're all the same, suppressing turnout.
There would be no better week for McCain than to have it spent with Axelrod and Black exchanging charges about the other side being liars.
Only the media can call out the lies. If the media won't do it, then it won't get done. The facts are out there. Obama's sardonic, consistent association of McCain and Bush is a much more effective message than getting sucked into a debate about lies over earmarks.
Obama is calling McCain out on the falseness of the Maverick brand, and on the Bridge to Nowhere: