Two questions come to mind, and only the second one is rhetorical.
- Have the bloggers who are demanding verification of the journalists' sources taken a position on whether Robert Novak should disclose his source(s) in the Intimigate (Valerie Plame) matter?
- Does any sane person seriously doubt that the "money quote" from the memo accurately reflected the thinking of the GOP leadership in Congress ("This is a great political issue...and this is a tough issue for Democrats.")?
On the second point, I'm not saying you have to accept that political strategery was the only motivation for every GOP politician who supported the Schiavo bill. The underlying moral questions are difficult, and an honestly held opposition to terminating nutrition in these circumstances presumably affected the judgment of some of the bill's supporters. But is it really plausible to suggest that Tom DeLay and Bill Frist weren't out to make political hay?
Which is why the forgery issue is a non-issue. If the document were forged, that would be a serious matter for the journalists involved and would send another reminder about the need to be careful in the increasingly time-pressured and competitive business of gathering news. But politically, the memo doesn't really matter much. People watched this grotesquery play out on their TV screens, and they saw DeLay and Frist and the others, and they (mostly) concluded that this was a bunch of political grandstanding. The memo merely confirms what the majority of the public already knew. Yes, the "Rathergate" memo also contained factual assertions that were, at least in large part, true. But that wasn't generally known amongst the public, and with the Swift Boat Liars on the attack, most independents probably figured the Dubya/AWOL stuff, along with the noise about Kerry's war record, was a bunch of he-said, he-said where voters were never going to find out the truth.