The linked blog entry and accompanying comments are by an large informative of the issues and respective positions.
In my view, while recognizing that Minnesota courts are desperately underfunded, the cost of U.S. legal services is already extreme. Raising the cost by adding a tax (I do not believe that lawyers could or would lower the underlying fees to keep gross cost constant) would put the courts still further out of reach for many meritorious cases than they already are. This, in turn, would further weaken one of the critical and key institutions that distinguishes the United States from its global competition and that creates a huge competitive advantage for American business. (Compare, for example, China where corruption involving judges is believed by many to be severe and the justice system is regarded by many as badly compromised.)