When President Donald Trump stops talking about a “bill of love” for “Dreamers” and instead claims that Democrats want to open the floodgates of illegal immigration; when his party puts out a grotesque ad accusing Democrats of complicity in murders committed by illegal immigrants, we should not be surprised. The Washington Post notes, “Trump has repeatedly sought to paint immigrants as dangerous, talking about transnational gangs, such as MS-13, and implementing a travel ban on travelers from some countries in the Middle East and Africa over what he said were concerns about terrorism.”

That is contrary to reality, but hard facts do not impede the anti-immigration crowd.

Unfortunately, antagonism toward immigrants and a preference for white Europeans over brown and black people remain the default setting for Trump and increasingly for his party. We need not revisit Trump’s long history of racism, but it’s time to acknowledge that many Republicans view his appeals to white grievance as a positive feature. It’s behind their obsession with “Telling it like it is” — code for expressing base prejudices. The rejection of Hispanics as real Americans has become a given among state-TV hosts like Tucker Carlson.

Trump now and then will lean toward a deal for the Dreamers or sound sympathetic toward legal immigrants for a moment, only to be snatched back into xenophobic mode by the anti-immigration vanguard in the House and Senate and by advisers like Chief of Staff John Kelly and senior adviser Stephen Miller, enthusiasts of such measures as the Muslim ban and the attack on local law enforcement that do not enable indiscriminate deportation. When Senate Majority Leader Mitch McConnell takes to the floor to claim Democrats care more about illegal immigrants than sick kids or the military, you see how vital the race/immigrant card has become to the GOP’s unity.

In many ways, antagonism toward immigrants is the glue that binds Trump to his followers and Republicans to one another. The Post reports:

“Conservative activists have also been cheered by the dramatic shift in Republican focus, which has followed the White House’s embrace of nativist language that casts the standoff as a choice between government funding for ‘lawful citizens’ and the ‘reckless demands’ of ‘unlawful immigrants.’ . . .

“But Trump proved in the 2016 election that immigration unified the GOP much more effectively than did its traditional focus on reducing entitlement spending, free trade and low deficits. Among the GOP base, the populist issues of trade and immigration are now far more animating than even abortion or taxes.”

This is not simply one issue of many. Robust legal immigration is a mainstay of dynamic capitalism; it demonstrates fidelity to the Founders’ vision that the country be defined not by race or ethnicity (blood and soil) but by adherence to the ideals of the republic. So much for that. In the current version of Republicanism, the Founders’ ideal is replaced by commitment to white, Christian nationalism (keep Muslims out, protect evangelical Christians’ right to refuse service to gays) and opposition to markets (government run-protectionism). That vision is frightening and antithetical to the experience of many Americans, but it is one onto which working-class whites in sufficiently large numbers latched, thereby lifting Trump to victory. What many viewed as implicit in Republicans’ messaging and issue choices (the so-called Southern strategy) is now open and unabashed.

Instead of standing athwart history screaming “Stop!” as conservative icon William F. Buckley Jr. urged, the GOP now stands athwart demographic reality screaming “Stop!” Frankly, I never understood why a movement would take pride in rejecting modernism (rather than shaping it, conserving what is good and discarding what is not), but on top of that, stopping a huge demographic shift — the largest, most diverse generation in history (millennials) supplanting aging baby boomers — seems futile and irrational.

The retreat into ethno-nationalism is no small matter but rather goes to the very definition of America and the core questions the Civil War, the civil rights movement and every wave of anti-immigration sentiment have presented: Who is an American? Does America need immigrants to prosper and to renew its creed in each generation? Trump and this iteration of the Republican Party have made aversion to diversity such a vital principle, it cannot be considered trivial. This is how Republicans have chosen to define themselves these days — and why many of us can no longer call ourselves Republicans.

Jennifer Rubin writes the Right Turn blog for The Post, offering reported opinion from a conservative perspective. She came to The Post after three years with Commentary magazine. Her work has appeared in a number of print and online publications, including the conservative Weekly Standard, where she has been a frequent contributor.