If all you care about, and I mean “all”, is making rich people richer, or you’re a “single-issue voter” who only cares about something like abortion or guns, or you’re a stone-cold racist,  he’s your candidate. Thomas Edsall of The New York Times, with the assistance of several studies, explains the seemingly unfathomable behavior of millions of others:

The center-right political coalition in America — the Republican Party as it stands today — can be described as holding two overarching goals: First, deregulation and reductions in corporate and other tax liabilities — each clearly stated on the White House website — and second, but packing a bigger punch, the preservation of the status quo by stemming the erosion of the privileged status of white Christian America. . . .

Last week, I argued that for Democrats the importance of ethnicity and race has grown, not diminished, since the mid-1960s. The same thing is true for Republicans — and many of the least obvious, or least comprehensible, aspects of Republican political strategy have to do with the party’s desire to cloak or veil the frank racism of the contemporary Republican agenda.

Robert P. Jones, the founder and C.E.O. of the Public Religion Research Institute, in his 2014 book, “The End of White Christian America,” described the situation this way:

America’s still segregated modern life is marked by three realities: First, geographic segregation has meant that — although places like Ferguson and Baltimore may seem like extreme examples — most white Americans continue to live in locales that insulate them from the obstacles facing many majority-black communities. Second, this legacy, compounded by social self-segregation, has led to a stark result: the overwhelming majority of white Americans don’t have a single close relationship with a person who isn’t white. Third, there are virtually no American institutions positioned to resolve these problems. Social segregation persists in virtually all major American institutions.

Firm allegiance to the conservative agenda has become crucial to the ability of Txxxx and the Republican Party to sustain the loyalty of an overwhelmingly white coalition that experiences itself as besieged and under the threat of losing power. The time when a major political party could articulate a nakedly racist agenda is long past, although Txxxx comes as close as possible.

“Txxxx goes all-in on race,” declared the headline on a story in Politico just after the close of the first night of the Republican convention on Monday.

While some speakers portrayed Txxxx as a friend of Black America, “others took a harder-edged tack that undercut the message of inclusion,” according to Politico. . . .

In a series of studies published from 2014 to 2018, Maureen A. Craig and Jennifer A. Richeson, professors of psychology at N.Y.U. and Yale, demonstrate how whites, faced with the prospect of becoming a minority, have embraced the Republican Party for institutional protection of their imperiled status.

In their 2014 paper, “On the Precipice of a ‘Majority-Minority’ America: Perceived Status Threat From the Racial Demographic Shift Affects White Americans’ Political Ideology,” Craig and Richeson took a national sample of whites who said they were unaffiliated with either political party and broke them into two groups.

One group was asked “if they had heard that California had become a majority-minority state,” thus making the issue of white minority status salient, and the other was asked “if they had heard that Hispanics had become roughly equal in number to Blacks nationally,” with no reference to the status of whites.

At the end of the survey, participants were asked whether they leaned toward either party. Those who had been informed about the minority status of whites in California said they leaned to the Republican Party by a margin of 45-35. Those who had not been informed of whites’ minority status leaned to the Democratic Party 40.5 to 24.3.

In a subsequent 2018 paper, “Racial and Political Dynamics of an Approaching ‘Majority-Minority’ United States,” Craig and Richeson . . .  reported that “whites for whom the impending racial demographic changes of the nation are salient” endorsed more conservative positions on a variety of policy issues and reported “greater support for Republican presidential candidate Dxxxx Txxxx.”

According to Joshua Greene, a professor of psychology at Harvard and the author of “Moral Tribes: Emotion, Reason, and the Gap Between Us and Them,” Txxxx is expert at sending “signals that are music to the ears of his base,” signals that ineradicably affirm his membership in the populist right wing of the Republican Party.

Greene argued in an email that when

Txxxx says that a judge of Mexican ancestry can’t do his job, or attacks women for their physical appearance, or makes fun of a disabled reporter, or says that there are good people on both sides of a violent neo-Nazi rally, or that Haiti is a “shithole,” or that the “Second Amendment People” can maybe do something about Hillary Clinton, Txxxx is very deliberately and publicly excommunicating himself from the company of liberals, even moderate ones.

In Greene’s view, Txxxx offers a case study in the deployment of “costly signals.”

How does it work? Greene writes:

Making oneself irredeemably unacceptable to the other tribe is equivalent to permanently binding oneself to one’s own. These comments are like gang tattoos. And in Txxxx’s case, it’s tattoos all over his neck and face.

At the same time, Txxxx’s “costly signals” make his reliability as a protector of white privilege clear.

John Tooby, a professor of anthropology at the University of California-Santa Barbara, described the signaling phenomenon in a 2017 Edge talk as an outgrowth of what he calls a “coalitional instinct.”

“To earn membership in a group,” Tooby says, “you must send signals that clearly indicate that you differentially support it, compared to rival groups.”

This, Tooby notes, encourages extremism: “Practical and functional truths are generally useless as differential signals, because any honest person might say them regardless of coalitional loyalty.” Far more effective are “unusual, exaggerated beliefs,” including “alarmism, conspiracies or hyperbolic comparisons.”

The success of Txxxx’s strategy will have long term consequences for the Republican Party, in Greene’s view:

Txxxx won over the base by publicly sacrificing his broader respectability. Back in 2016, the other Republican primary candidates looked ahead at the general election and thought this was a losing strategy. But Txxxx pulled it off, perhaps because he didn’t really care about winning. But now he owns the party. No Republican can get elected without the Republican base, and the Republican base trusts Txxxx and only Txxxx, thanks to his costly signals.

. . . The Republican Party is now the home of white evangelical Christians and the residents of rural, small town America who see their privilege — what they experience as their values and culture — under assault from a rising coalition of minorities, feminists, well-educated liberals and veterans of the sexual revolution.