Your disparager's presumption that you must be arguing in bad faith is one of the most tedious features of the age.
Naughty liberals, Nasty liberals. Making specious claims of bad faith against arguments made by the Warriors for Truth. I guess he's just getting sick of hearing it.
The "disparager" in question is Matt Yglesias, who strikes me as an unlikely choice of target in this context. I don't know enough about Levin's views on the subject of farm subsidies to know whether Yglesias' claim is true. I do know enough about Yglesias to assert that he's a pretty careful partisan and doesn't generally make unsupportable claims.
Update: Yglesias Responds to Jonah and others who have weighed in.