I'm sorry that he has Parkinson's. He is far from the worst on the left and actually tries to use logic to make an argument
Yes, he does try to "construct" his column more than say, E. J. Dionne, but he often enough lapses into appeals to authority and thinly disguised ad hominems. He has also been much more shrill in his cable appearances (particularly since the Parkinson's overtook him). I have no use for him.