In thinking about the new service sales tax I wondered - knowing that a "normal" sales tax percentage increase requires a vote of the people under the Michigan Constitution, why would an increase from 0% to 6% on previously untaxed services not constitute an increase that only the people could legally approve?  

The answer to this question requires boning up on your Michigan Constitution, notably, Article 9, Section 8 (I've highlighted for emphasis, but unfortunately RM's engine doesn't show them the same as OL's, so you'll have to go there, or just look at the bolded words):  

§ 8 Sales and use taxes  

Article 9, Sec. 8.

Except as provided in this section, the Legislature shall not impose a sales  tax on retailers at a  rate of more than 4% of their gross taxable sales of tangible  personal property.

Beginning May 1, 1994, the sales tax shall be imposed on retailers at an additional rate  of 2% of their gross taxable  sales of tangible personal property not exempt by law and the use tax at  an additional rate of 2%. The proceeds of the sales and use taxes imposed at the  additional rate of 2% shall be deposited in the state school aid fund  established in section 11 of this article. The allocation of sales tax revenue  required or authorized by sections 9 and 10 of this article does not apply to  the revenue from the sales tax imposed at the additional rate of 2%.

No sales tax or use tax shall be charged or collected from and after January  1, 1975 on the sale or use of prescription drugs for human use, or on the sale  or use of food for human consumption except in the case of prepared food  intended for immediate consumption as defined by law. This provision shall not  apply to alcoholic beverages.

Special thanks to attorney Greg Schmid for sending that clip to me when I asked him the question of Constitutionality.

Reading that, it seems pretty cut and dry.  The legislature can NOT authorize a sales or use tax on non-tangible property, and no tax on any property, tangible or intangible, can exceed 6%.

The legislature has expanded the sales tax to include dozens of categories of intangible property.  Unconstitutional?  The only argument I can imagine is that the "new" tax is truly new and not a "sales" or "use" tax and entirely separate from the tax described here, and hence there is no limit to taxation of intangible property or services.  Under this stretching of the Constitution, the government could charge a 100% tax on services, and the words "sales" or "use" have no meaning.

Folks, I think we have an unconstitutional tax that could be challenged in court.  To my knowledge, no one yet has put this idea in print. 

But I invite the lawyers out there (many of whom will be paying the double (because you're paying income tax on it too) service tax, by the way) to vette the idea.  I don't think you'll have to look far for clients, either.