My concern with such an attitude is that it demeans a person's desires to speak out and marginalizes a voice, based upon an association which is legal (especially when that association is with someone who attaches himself to any publicity he can find).
The irony is that both left and right do it to each other and it is just as insulting to the rest of us at any time. Did the supporters of the Schaivo family think her parent's voices should be marginalized because of their association with radical right-winger and gadfly Randall Terry (formerly of the not-mainstream-"prolife" organization Operation Rescue) and others? No, but some members of the left did. Now, those formerly quiet members of the right that did not question Randall Terry's association with the Schaivos scream that Cindy Sheehan is a puppet for Michael Moore and the left wing.
Who cares? In a country which celebrates diversity of voices and the freedom of speech, every voice should be heard, even when we do not agree with what it expresses. I think much of the right is (rightly) concerned because Sheehan has caught on with mainstream America. To marginalize this grieving mother of a dead soldier is to say that only those with proper credentials should have a voice to be heard (it was the same with the Schaivos also).
Sheehan's protest and argument needs to be judged, but on its own merits, not Michael Moore's. Here is an interesting quote from the piece I mentioned.
A comment on the left-wing website Daily Kos described Sheehan as ''Terri Schiavo reincarnated." I believe this was meant as a compliment. But actually, the Sheehan circus has a lot in common with the Schiavo circus, none of it good. Both stories represent a triumph -- on different sides of the political divide -- of emotion- and sentiment-driven politics. Schiavo's parents could go off on paranoid, crazy, vitriolic rants, and enjoy a certain immunity by virtue of their unthinkable tragedy. The same is true of Sheehan.
Sheehan's grief entitles her to sympathy, which is why I believe the president should have granted her the meeting she wanted. (On pragmatic grounds, it would have also taken the sting out of Sheehan's protest.) But her loss does not give her, as New York Times columnist Maureen Dowd has claimed, an ''absolute" moral authority -- any more than it would if her reaction to her son's death was to demand a US nuclear strike against the insurgents.