That IS the whole point. It isn't clear from the videos themselves that the police should have stepped in at all. Maybe they should have just let him rant for a bit longer and see where he was going with it. It sounded like Senator Kerry expressed a willingness to answer the questions that were posed, altho I think he should have been more forceful in getting this message across. While this man's demeanor was sarcastic and somewhat annoying, it was not clear to me that he was going to become a real problem. Annoying, perhaps, but a problem, not yet. I think SOMEBODY jumped the gun, with the result that the police took action when they should have stood back and done nothing. So just exactly who that SOMEBODY is, remains murky, and cannot be determined from the video.
So instead of a minor irritation to liven up the session, they ended up with a major incident including a tazering and an arrest, and bad publicity, and maybe they could have avoided it all by just standing back for a couple more minutes to see where this was all going. It might have just blown over after a brief exchange between the student and Senator Kerry, which Kerry apparently was willing to engage in.
Can we all agree that it's just possible that a politician may well seem to be willing to answer and making all the right noises, while simultaneously really be simply stalling long enough for the moderator, handlers, or whoever to get the person causing the problem out of the way? After all, I don't think any politician is going to want to end up on YouTube or the evening news for saying "Shut up; I don't want to answer your silly questions!"
Now, with that out of the way, let me address something else. As a general rule, when you call the cops, we are there because asking nicely hasn't worked. While there's no hard and fast rule for when we stop asking, the point comes when we will make you comply. And we cannot lose. As I posted a while ago, I generally will ask once, tell once, and then I will enforce compliance with whatever force is necessary. In this case, I don't know... I suspect the campus cops just may be familiar with this particular student. There are people that I won't ask once where I work; if I'm called in, they've been asked, and they've been told. I know them; I know that I will have to make them comply. I bet every cop posting here can think of several folks in that category... And there are people on the other end, that I'm going to ask, almost beg, before I take action. I just don't think the chief is going to think well of me manhandling a cantankerous 85 year old out of a council meeting without trying everything possible, and then some, to get them out without force...
In this case -- I don't care whether or not the kid should have been silenced. That's really an entirely separate question from whether the use of force in this case was reasonable. Once the cops were asked to get him to stop, he had a simple choice: comply, or be made to comply. He could have simply sat down, then used his free speech rights to complain via the press, or the internet, or whatever, how Senator Kerry wouldn't answer him. ANY policitian's appearance is an orchestrated show. It's not uncommon for the "spontaneous audience questions" to be anything but spontaneous, and even vetted and approved before hand. (And, every once in a while, someone sneaks in a different question when they're given the microphone!)
Police are allowed, and often required, to use reasonable force to effect various societal goals, up to and including physical arrest of a person. In the case of a person disrupting an otherwise peaceable assembly on private property, when those in charge of the event, exercising care, custody and control of the property request that a person causing a disruption be removed -- the police have the duty to remove that person. Sometimes, all it takes is showing up, and silently encouraging compliance with the request to leave. Other times, more force is required. Again, in the instant case, not only did the person causing the disruption refuse to cease the disturbance, he actively resisted lesser efforts, and forced his way back into the area. At that point, more force becomes necessary.
The simple truth is that you don't win by arguing or fighting the cops. If they tell you to leave -- leave. Argue it later. Because at that point -- you won't win, no matter how sure you are that you're right. You may win later -- but at that moment, you'll lose. Follow good military advise; to paraphrase Sun Tzu, know when to fight and when not to fight, and you'll win.