Read what the founding fathers say about succession and then tell me that again.
OK, look at what Madison had to say about the concept of nullification or unilateral secession and get back to me. The idea that a state may secede from the Union may be supported. The idea that a state may do so without the consent of the other states is ridiculous.
As Non-Sequitur has pointed out in the past, there are a number of Founders that considered Federal power to be superior to States, and these are the ones he will tend to quote.
There was no "unanimity" in the Founding era, just as there is none today. We, of course, can continue to point to a number of prominent Founders ourselves that uphold our argument for secession, and he will continue to quote those that deny it.
(If you look at the debates, and the resolutions passed by the states, in order to accept the Constitution of 1787, there is a clear and undeniable right to seceed from the Federal compact expressed by nearly every State. NS tends to -and please, NS, correct me if I'm misrepresenting you, as that is NOT my intent- suggest that these were merely political ploys, and that the Federal compact, by nature of being an extension of the "eternal" Articles of Confederation, supersedes all State authority, and that no State can claim sovereignty. I could not possibly disagree with these sentiments more strongly, but NS is as entitled to his opinion on the matter as I am.)