Actually, MT, you seem to think the generic term "the government" only aplies to the brief you are reffering to. Seems to me "the government" also filed the one Lazs is reffering to. Maybe you're just trying to cloud up the very valid point he's making?
The brief linked by lazs has 9 democratic senators signing, so there's not a clear party line on it. There's no hint that it was witheld from some people in order to make them look bad. I think it's very reasonable to assume that if someone didn't sign the brief, they didn't want to.
Maybe you should ask yourself a simple question: "If Hillary and Obama chose not to sign it, what would that mean?"