One of my "Nullification Soul Mates" in the blogoshpere Jim Gourdie, over at Conservatives on Fire, brings us I Repeat _ Nullification is Valid and Obama Has Shown Us The Way!
He has also posted a link to Publius-Huldah article The Oath Of Office: The Check On Usurpations By Congress, The Executive Branch, & Federal Judges.
More:
Adrienne: More on Nullification...
Tom Woods: Nullification: Answering the Objections