Trump’s successful deployment of the issue of immigration to mobilize voters raises this question: Why is his opposition to immigrants and Mexicans in particular so resonant when immigration liberalization ostensibly has majority support in most polls?

Research conducted by Lefteris Jason Anastasopoulos, a lecturer and data science fellow at Berkeley’s School of Information, provides one answer: Support for immigration “may be greatly overestimated.”

In an email, Anastasopoulos writes that

polls conducted by large survey organizations never ask about immigration in geographic context. Instead they ask questions about whether respondents support increasing immigration or granting amnesty for undocumented immigrants in the “United States” overall rather than, say, Dayton, Ohio, or Wilmington, North Carolina, places where immigration has been rapidly increasing over the past few years. This kind of abstract framing tends to push respondents toward giving more “politically correct” answers to standard poll questions about immigration.

The result is

a significant underestimation of the backlash against newly arriving immigrants and an overestimation of the support for immigration among the public.

The refusal of Democrats and the American left to hear — or to grant some legitimacy to — the grievances of white America as it loses power and stature to ascendant minorities and to waves of immigrants from across the globe undergirds the Trump movement. In the zero sum world of immigration politics, it has proved impossible so far to convincingly affirm the validity of the claims of both sides.

The quest by American liberals and progressives for support, or at least tolerance, of diversity, inclusiveness and multiculturalism is likely to prevail — particularly if the compulsory dimension of compliance is curtailed.

Jonathan Haidt, a professor at N.Y.U., suggested to me that one way to better understand the intensity of Trump’s appeal is by looking at something called “psychological reactance.” Haidt describes reactance as

the feeling you get when people try to stop you from doing something you’ve been doing, and you perceive that they have no right or justification for stopping you. So you redouble your efforts and do it even more, just to show that you don’t accept their domination. Men in particular are concerned to show that they do not accept domination.

The theory, first developed in 1966 by Jack W. Brehm in “A Theory of Psychological Reactance,” is directly relevant to the 2016 election, according to Haidt. Here is Brehm’s original language:

Psychological reactance is an aversive affective reaction in response to regulations or impositions that impinge on freedom and autonomy. This reaction is especially common when individuals feel obliged to adopt a particular opinion or engage in a specific behavior. Specifically, a perceived diminution in freedom ignites an emotional state, called psychological reactance, that elicits behaviors intended to restore this autonomy.

Haidt applies this to the 2016 election:

Translated to the Trump phenomenon, I would say that decades of political correctness, with its focus on “straight white men” as the villains and oppressors — now extended to “straight white cis-gendered men” — has caused some degree of reactance in many and perhaps most white men.

In both the workplace and academia, Haidt argues,

the accusatory and vindictive approach of many social justice activists and diversity trainers may actually have increased the desire and willingness of some white men to say and do un-PC things.

In this atmosphere, according to Haidt,

Trump comes along and punches political correctness in the face. Anyone feeling some degree of anti-PC reactance is going to feel a thrill in their heart, and will want to stand up and applaud. And because feelings drive reasoning, these feelings of gratitude will make it hard for anyone to present arguments to them about the downsides of a Trump presidency.

Trump’s anger at being policed or fenced in apparently speaks to the resentment of many American men and their resistance to being instructed, particularly by a female candidate, on how they should think, speak or behave.

On April 26, Trump wheeled out a spectacularly offensive attack on Clinton, perhaps designed to provoke the response it got. He accused her of playing “the women’s card” when “she has got nothing else going. Frankly, if Hillary Clinton were a man, I don’t think she would get 5 percent of the vote.”

Hillary rose to the bait. Three days later, appearing on Jake Tapper’s CNN show “The Lead,” she countered:

I have a lot of experience dealing with men who sometimes get off the reservation in the way they behave and how they speak. … I am not going to deal with their temper tantrums, or their bullying or their efforts to try to provoke me. He can say whatever he wants to say about me, I could really care less.

Trump responded on Sean Hannity’s Fox News show on May 2. What Clinton said “was a very derogatory statement to men,” Trump declared. “It was almost as though she’s going to tell us what to do, tell men what to do.” He continued, “It was a real put-down.”