The flaw in your argument about Hoffman and the pledge you claim he made was that if he ever said such a thing, he would have been referring to a Republican candidate, not a Dem. Scozzawhatever is no Republican.
"Doug Hoffman looked me in the eyes, raised his right hand and pledged to support the Republican nominee in this district. He then turned around and declared his candidacy for this seat, rendering his oath utterly meaningless. Doug Hoffman lacks the basic integrity we need in our Congressional Representative." -- Jefferson County Republican Party Chairman Don Coon