A marketing pro named Patrick Strother wants to trademark the governor's budget proposal as the StupidTax, and wrote a scathing blog post about it.
It's a pointed example of the criticism the business-to-business services tax has received. (Related: At this point the B2B tax is mission-critical for the governor's budget, if the numbers are going to work. The tax raises enough new revenue to erase the projected $1.1 billion budget deficit twice over, allowing for a lower sales tax rate overall and the promised $500 property tax rebate for Minnesota homeowners.)
Economic policy and budget details aside, though, Strother's campaign illustrates the type of people who generally lobby hardest against a sales tax on professional services. They are lawyers and accountants, professionals in marketing and advertising, plus the IT and consulting communities, and the media.
As John Siegried and Paul Smith put it in a 1991 article in the National Tax Journal, “A tax on business inputs has a very substantial direct impact on a small number of politically astute and sophisticated taxpayers.”
In general they have money, political influence, and as Strother illustrates, they know how to communicate.
Siegried and Smith were talking about the example of Florida, the last state to pass a sales tax on professional services. It was repealed six months after it went into effect in 1987. 
On Tuesday I asked Myron Frans, Minnesota's commissioner of revenue, whether he was cracking under pressure from the powerful lobbies opposed to the tax. He laughed.
"We're taking a lot of comments, but that's OK, the debate is important and it's a part of the process," he said. "We're enjoying it as much as you can."
UPDATE: Brian Bakst of the AP notes that Strother was a paid consultant for the Minnesota GOP in 2010, earning $30,000 that year.