The violence that broke out Thursday night in San Jose, California, during and after a Donald Trump rally has raised fears that the next five months will see increasingly heightened confrontations between Trump protesters and admirers. It’s also led to the frightening thought that violent resistance to a candidacy based on the promise of violence might in some quarters be considered a rational strategy.

To discuss what the protests mean and how to think about the ways to oppose a candidate who makes frank appeals to racism and xenophobia, I called up Todd Gitlin, an expert on politics and the media and a professor of journalism and sociology at Columbia University. He has has written extensively about the 1960s and protest movements. Our conversation has been edited and condensed.

Isaac Chotiner: What did you make of the events in San Jose Thursday night?

Todd Gitlin: My thoughts ran back to an incident in San Jose in 1970 when Nixon was speaking from a rally and got up on his car and he flashed his V-sign with a big grin. Later, he said to one of his hangers-on, “They hate it when I do that.” He was courting a venomous display of rage. I don’t think Trump was necessarily deliberately inciting this, but I think he properly regards these collisions as food for his wilder beasts, and he loves it.

Another thought was, who knows who these people are? Might some of them be agent provocateurs? It wouldn’t be the first time, and it doesn’t mean all of them are, and it doesn’t mean that there are not authentic feelings of rage directed at Trump. But it wouldn’t be surprising if there were agent provocateurs nibbling around the edges. You have Roger Stone working with Trump, an old-time dirty trickster.

The lead story in the New York Times right now is about a Trump victory being a real threat to the rule of law. Lots of people have thrown around the word fascism, not altogether wrongly I don’t think. So in a sense do you think people are responding rationally to the possible threat they see?

I think it is likely to be counterproductive. On the other hand there is a nonzero threat of massive deportation and assault directed against Latinos and Muslims and whatnot. I think the anger is entirely justified. Playing it out by going up and punching people is dumb but hard to control.

Are you certain this plays so badly for the anti-Trump cause? I think it very well might, but I wonder if it will be able to be spun the same way as antiwar protests, i.e., as anti-American. This is protesting someone whom over half the country strongly dislikes and who people know has already tried to instigate violence.

It’s not clear how this plays. My working thought is that there is a core of Trump devotees, where every Trump slur and crudity revs up their enthusiasm. These are the people who think Obama is a Muslim. Then we have, around that molten core of venom, a concentric circle of people who hate Hillary and job loss, and it’s not a sure thing that they will rally to Trump when they see what they think is a left-wing mob going after his loyalists. Some might feel that way. Others might feel that things are breaking down and therefore he is not a force of order; he is a force of decomposition. Those are both possibilities. Do they fear he means mayhem in the streets, or do they herald the emergence of the man with the jutting jaw?

One of the attackers had a Mexican flag T-shirt tied around his neck. This was a bad development when Proposition 187 was on the ballot in California and Mexican flags appeared, and there was a recoil. The pro-immigrant position became framed as unpatriotic.

But putting aside the practical consequences, is there some point where you feel that peaceful protest is not enough?

Well, some people have been saying that, including people in Chicago, which led Trump to cancel his rally. It was said that people had clogged the streets to prevent people from getting to the rally. That is the sort of rhetoric we are starting to hear, and I think we will hear more of it. I understand the viewpoint of people who say the danger is clear and present and the opposition deserves to be escalated. I am dubious about whether that is desirable.

Does any part of you think that this guy is yelling hate speech and that people should oppose him regardless? Am I wrong in thinking some part of you thought people should go protest Vietnam, even sometimes violently, because of the scale of the awfulness that was happening?

I think there is a much stronger case to be made that the violent, more confrontational turn in the anti–Vietnam War movement set back the cause of war opposition. On balance, I think there is no doubt about it. One of the people who bombed the research center in Madison, who was convicted and did time, still believes that while this set back the movement in Madison—which by the way killed a graduate student who was anti-war—it was not harmful and actually beneficial for the national movement. But I am more inclined to go along with people who say the opposite. Paul Soglin was one. He was a member of the city council and later the mayor, and he is quite convinced it set back the antiwar movement.

And so was Mark Rudd, who was quoted in this book I just read as saying that we, the Weather Underground, were the intellectual authors of the bombing. I am with Soglin and Rudd on this. I think the movement was seriously battered by acts of transparent violence, and not a lot of distinctions were made throwing a firebomb and actually blowing people up. The Weatherman were prepared to do a lot more of it.

I certainly understand rage. I have no trouble performing the human act of understanding, but I think you are setting yourself and everyone else up for backfire when you make yourself and your rage the center of attention and the story.

Read more Slate coverage of the 2016 campaign.