As the protesters neared the exit,

a woman suddenly lunged for the audio equipment, pulled leads out indiscriminately, and knocked some of the equipment to the floor. The microphones stopped working. Another protester shoved a student volunteer into the door.

What caused this extreme reaction?
A bunch of farging idiots who think disagreeing with them is violence and shouldn't be allowed.  Aided and abetted by idiot journalists
...After the incident, however, the disruption and violent misconduct were downplayed. Willamette Week, a left-wing alternative newspaper, was dismissive: “[The Freethinkers] expected controversy. They warned of violence. None arrived.” Perhaps not the kind of violence that had been threatened, but there was intentional “criminal mischief,” hundreds of dollars in property damage, and unnecessary disruption lasting just over four minutes (not the 30 seconds the Willamette Week incorrectly reported).
who are sorry excuses for reporters.  As Insty has noted, 'Consider them Democrat operatives with bylines'.