Smearing the mother of a killed soldier is not only awful, it is also counterproductive. You can look at what she says--it discredits her without anything else needed:
MATTHEWS: All right. If your son had been killed in Afghanistan, would you have a different feeling?
SHEEHAN: I don't think so, Chris, because I believe that Afghanistan is almost the same thing. We're fighting terrorism. Or terrorists, we're saying. But they're not contained in a country. This is an ideology and not an enemy. And we know that Iraq, Iraq had no terrorism. They were no threat to the United States of America.
MATTHEWS: But Afghanistan was harboring, the Taliban was harboring al-Qaida which is the group that attacked us on 9/11.
SHEEHAN: Well then we should have gone after al-Qaida and maybe not after the country of Afghanistan.
MATTHEWS: But that's where they were being harbored. That's where they were headquartered. Shouldn't we go after their headquarters? Doesn't that make sense?
SHEEHAN: Well, but there were a lot of innocent people killed in that invasion, too. ... But I'm seeing that we're sending our ground troops in to invade countries where the entire country wasn't the problem. Especially Iraq. Iraq was no problem. And why do we send in invading armies to march into Afghanistan when we're looking for a select group of people in that country?
Well, that is rather easy to answer. Because we asked for Afghanistan to turn bin Laden over, and they refused (because he was very tight with the Taliban government). And if you don't think dying in Afghanistan is dying for a noble cause it is rather obvious that no chat with Bush is going to make you think that dying in Iraq was. No need to bring in extraneous junk in criticizing Sheehan. She is part of the "we shouldn't have invaded Afghanistan left" and merely needs to be identified as such. And if then she continues to serve as a rallying point for the left, the agenda becomes clearer.
Hat tip Balloon-Juice