Canniness is a virtue, at least for organizers. When protest goes well – the Women’s Marches, the airport demonstrations – it helps immeasurably, limiting the right’s ability to act or at least exacting a high price in political capital. But protest can go badly too, and when it does it gives the bad guys a gift.

I should have gotten a chance to see this close up last week, because Middlebury College in Vermont, where I teach, had a protest go mostly sour. But since my mother was taken to the emergency room early in the week, I was camped out in her hospital room, not on campus. Still, the picture of events that emerges from Facebook and campus chat rooms is fairly clear.

It began when conservative students at the college invited a man named Charles Murray to speak on campus. Murray is a professional troll – “Milo with a doctorate”, as one observer described him – who made his bones a quarter century ago with a vile book, The Bell Curve, arguing that intelligence tests showed black people less able. Academics of all stripes have savaged the book’s methodology and conclusions, but back in the day it was one of the many bulwarks of the nation’s ugly rightward and racist shift.

So, many students and faculty at Middlebury were mad that he was coming, as they should have been – it’s gross, in particular, that students of color should have to deal with this kind of aggressive insult to their legitimacy. But of course, that was the point for Murray and his enablers at the American Enterprise Institute: they’re trolls.

They want these kinds of fights, over and over, as part of their campaign to discredit academia and multiculturalism. And once some students had made the invitation, the die was cast, if only because Americans by and large believe that colleges and universities should be open to all ideas (and they’re probably right to think so, if for no other reason than it’s hard to imagine the committee that could vet what was proper and what wasn’t).

College authorities made their share of mistakes in the days that followed: there was no real reason for the political science department to officially support Murray’s visit, for instance. But other parts of the college reacted the right way: the math department, say, which held a series of seminars to demonstrate why Murray’s statistical methods were rubbish.

Instead, it was goodhearted campus activists – both some students and some faculty – that really fell for the troller’s bait.

Some began demanding that the college cancel the visit, and others threatened to prevent him from speaking. They failed at the first task but they largely succeeded at the second: when Murray arrived on Thursday he was greeted by a wall of noise, as protesters chanted and screamed him down.

When administrators took him off to a room where his remarks, and questions from a professor, could be livestreamed, a few people pulled fire alarms. When they tried to rush Murray from the building, a small throng, many in masks, blocked the car and sent the professor who had been escorting the racist to the hospital with a concussion.

The result was predictable: Murray emerged with new standing, a largely forgotten hack with a renewed lease on public life, indeed now a martyr to the cause of free speech. And anti-racist activism took a hit, the powerful progressive virtue of openness overshadowed by apparent intolerance. No one should be surprised at the outcome: in America, anyway, shouting someone down “reads” badly to the larger public, every single time. And it is precisely the job of activists to figure out how things are going to read, lest they do real damage to important causes – damage, as in this case, that will inevitably fall mostly on people with fewer resources than Middlebury students.

One way of saying this is – activism is a science with fairly predictable rules: history has shown what does and doesn’t work. And what doesn’t work is rage; what does work is dignity. That same week in Selma, the Rev William Barber (the North Carolina pastor and leader of the Moral Monday movement who is the closest thing contemporary America has to a Dr King) confronted a similar situation.

The state’s attorney general, in the Jeff Sessions tradition, came to an African American church to explain why his proposed voter ID laws were a good idea. It’s hard to imagine a more obnoxious man or setting: he was figuratively spitting on the graves of those who died in the Selma march for voting rights. But they did not shout him down: they simply got up and exited the church to hold a well-attended press conference outside. (Here’s typical coverage of that effort.)

Middlebury students that I’ve talked to were sad and annoyed that their “voices weren’t heard” amidst the melee. They’re right to be sad: the things they had to say about inclusion, about marginalization, and about the debilitating effects of pseudo-scientific racism were profound, and markedly more interesting than Murray’s recycled bile.

But they were wrong to be annoyed, any more than people who climb into a shower should be annoyed at getting wet. If you shout down a speaker, that’s what people will remember, period. If they’d wanted to be heard, then they needed, like the Rev Barber, to be more creative.

Imagine if they’d taken the available seats, and then got up and peacefully left, not shouting but singing, or in pure silence. Imagine, on the next campus where Murray takes his nasty road show, if students and faculty organize to shame the college community into boycotting the talk, and instead hold a teach-in outside. Imagine if they don’t take the bait.

This kind of discipline is hard work. I’ve spent much of the last decade helping organize protests large-scale and small; one key part of the planning always involves making sure that necessary anger doesn’t turn into self-defeating rage. That’s why there are trainings beforehand, and why people sign pledges of nonviolence, and why there are marshals from within the ranks to make sure people don’t break that discipline.

College students are completely capable of this (it’s with seven Middlebury students that I formed the climate campaign 350.org, which has gone on to organize more rallies in more places than perhaps any movement in history). But everyone involved needs to take it for the serious task it is, understanding that emotion is as much an enemy as a friend for activists. There’s no easy version of activism, any more than there is of physics or French or the other tasks college students seriously engage in. In fact, protest is probably a subject, like first aid or how to use the fire extinguisher, that college freshmen should learn.

Because there are going to be plenty of opportunities to try again in the years ahead, since trolling is more or less what Donald Trump and Steve Bannon do. There will be more Milos and more Murrays. When we strengthen their hands, we weaken further the most vulnerable people on our planet, be they immigrants facing deportation or southern black Americans facing voter suppression laws or peasant farmers facing rising oceans. That’s not right or wrong, that’s just how it works.