Sabato is one of the dumbest but extremely overrated political analysts in the country, he is always wrong in his analysis and predictions.
I was at University of Virginia with Sabato in the 70's - we were both undergrads - the loonie lefties in the Government Department (Political Science at most Universities) already worshiped Larry as a genius.
My guess is that many of the same worshipers now hold positions of influence and power in the MSM and entrenched Washington bureaucracy.