Bill Miller maintains two websites on secession that I follow: Secession & Nullification - News and Information, which reposts articles from various blogs on those subjects, and an educational site called Secession University.
His latest installment in Secession University states that the right of secession exists on the basis of three grand principles:
- The United States was founded on the right of secession
- The Constitution does not prohibit states from seceding
- The sovereign authority of the states -- a concept that he shows was supported even by Abraham Lincoln.
The interesting thing is, he relies solely on logic and documentary proof, not just from statements from the Founding Fathers or other similar sources. This article -- and both of Mr. Miller's websites, for that matter -- are well worth reading.