When you have one guy who doesn't know what the Defense of Marriage Act is and another who claims he is against the war and for the troops despite his opposite votes, I wouldn't have been stunned at all. Lieberman is probably the only one who could have answered that question.
Kerry has been saying he's for the troops but against the mission since he started campainging and as a way to distract from his "yea" vote. Ironically, or not so, the DNC came up with the idea of using that line from republicans during the Kosovo conflict, and Kerry is pretty polished in a way to make it sound nice (though considering how many lefties are hoping for our service men to die over there, its pretty safe to say its a lie and a talking point).
Edwards on the other hand, simply didn't care, he should have known about the Defence of Marriage act, for gods sake he's a lawyer and was a very well known and excellent one at that, it sounded like he had rehearsed what he was going to say well in advance, and still didn't know it, i.e. he had bad info and memorized it, or he went by what ever BS he heard and winged it.
Either way, there's no doubt that all of them, except for Sharpton and Kunich have definatley been tutored on this, and studied it, and know there talking points, walking around in congress alone should give them the basic info, whats the point of them having advisors and people to write there speech, tutor them, and giving them there talking points if they're just going to "wing it" through the campaign. They all would have been able to answer that question.