The opinion also nicely lays out the ironic backstory. As you may know, the Mifflin Street Block Party started during the student protest era, with a young firebrand named Paul Soglin at the forefront. Well, times change. Paul Soglin has now been Madison's mayor a bunch of different times, and he's pretty much a party-pooper nowadays. So it goes.
As for my own experience with the Mifflin Street Block Party, I can personally attest to the high quality of the brownies.