Fleming is a great american revolution historian but he is getting a lot of criticism for his position in his new book called "A disease in the public mind" which is:

Since the early days of the 19th century New England has always resented losing their political stronghold on the country to the south (think virginia dynasty & hartford convention). They saw themselves as the rightful heirs to the american political system because they were the birthplace of the american revolution. They latched on to the slavery issue because it was one of the few political stances that they could drum up serious political support for it and was a nice way to get back at the south.