There are 2 Thomas Flemings.
Caution should be applied because I have mistakenly confused them. They are quite different people.
This is the guy who appears on the History Channel, who has written novels, books on the Revolution, and revisionist studies of Wilson and Roosevelt. It's not the Chronicles guy. They're both kind of cranky, but this guy is sort of the loveable old Irish crank down the street, not the bearded ideological wild man the other one is.
His "new interpretation" goes back to what people were saying a century ago. It was the fault of the abolitionists who upset the political balance. He strongly implies that they were upset at New England's loss of power within the country and were using slavery to get their own back. That was probably what Fleming's teachers learned when they were in college and what they taught him in school.
It's not really a "new interpretation" and it doesn't really engage with what historians have been talking about in recent years. He doesn't take slavery all that seriously, in comparison with more recent writers.
The other half of his argument -- that fear of race war or racial uprising -- was behind Southern thinking and feeling at the time, chimes in all too well with contemporary debate on the causes of the war. I'm not sure how far you want to go down that road though. Fleming does come up with some interesting period details, though.