The American struggle between our better angels and inner demons has ebbed and flowed through our history, as a nation founded on the idea of citizens vested with inalienable rights and equal before the law has contended with the forces of nativism, bigotry, and privilege.

Virtually every advance in expanding individual rights, equitably sharing the nation’s abundance, creating equal opportunity for its citizens and welcoming the stranger has been met with a forceful reaction to resist, deny or eliminate these gains.

The 13th, 14th and 15th amendments of the post-Civil War era were effectively nullified by the South’s “Redemption” that followed on the heels of Reconstruction, imposing almost a century of Jim Crow on Southern blacks. The Great Age of Immigration from the 1880s to World War I was met with a nativist reaction culminating in the restrictionist laws of 1921-1924 whose quotas effectively barred mostly Italian and Jewish immigrants from Southern and Eastern Europe.

The 40 years of reform from the New Deal through the Great Society that created a safety net for the nation’s vulnerable, institutionalized labor rights, forged a progressive tax system that narrowed the gap between rich and poor, and created agencies to protect the public from corporate excess were swept away by the Reagan revolution and the ethos of “Greed is Good.” The seminal Civil Rights legislation of the Great Society in the mid-1960s that restored civil and voting rights to blacks in the South led to a massive defection of whites there from the Democratic Party. And the 1965 Immigration Act that finally did away with the racial quotas of the 1920s produced an unanticipated influx of non-European newcomers that generated a fierce nativist response with its attendant cruelties.

All these toxic strains have come together in the ascendancy of Donald Trump and his congressional partisans who have engaged in widespread voter suppression aimed at effectively disenfranchising whole strata of minority voters; massive immigration restriction fueled by a campaign of racist vilification; a further erosion of labor rights; a rollback of the safety net from food stamps to Medicaid; and an assault on the regulatory agencies that protect the American public from corporate predators, environmental degradation, and the vicissitudes of the market. All this has been accompanied by a go-it-alone unravelling of America’s postwar alliances that had served as a bulwark against the nation’s global enemies.

One can only marvel that an agenda so antithetical to the interests of most Americans propelled Trump into the White House. And while there are many reasons for his success—including the culture of celebrity, the fragmentation of social media, the tilted electoral system, the miscalculations of his opponents, the ill-attended grievances of fly-over America—it is the fear of demographic demise that most energized Trump’s constituency as he rode a wave of xenophobia into office. His opponents’ invocation of bread-and-butter issues, much less facts, proved no match for Trump’s naked appeal to emotion. Rage itself has become a plank of his Republican Party.

The American hydra of nativism, racism and isolationism has long lurked in the bowels of our body politic. It awaited only the man, and the moment. In the last century it was made manifest in the ascendance of the Ku Klux Klan during the 1920s, the intense opposition to admitting Jewish refugees fleeing Nazi rule in the late ’30s, the right-wing Populism of such anti-Semitic demagogues as Father Coughlin, with his vast radio audience, and the isolationist message of the America First movement and its icon Charles Lindbergh who, despite his unsavory dalliance with Hitler, became a hero to many on the American right.

It is no accident that 1893 saw both the institution of the first segregation laws in Mississippi and Republican Senator Henry Cabot Lodge’s initiative to introduce “literacy tests” to prevent “undesirables” from immigrating, the first step in a campaign of racialist exclusion that would culminate within 30 years in the National Origins Act. While distinct phenomena, racism and nativism went hand in hand in using a bogus “scientific” theory in which the “superior” Nordic race saw itself threatened by lesser breeds from abroad and inferior blacks at home. The solution was a dual policy of barring immigrants and repressing blacks to maintain racial purity, and political hegemony.

A chronicle of the political debate over restriction, segregation and isolationism during those years shows the same names cropping up. The racial theorist Madison Grant, author of The Passing of the Great Race: Or, The Racial Basis of European History made common cause with Stanford University President David Starr Jordan, a leader of the eugenics movement who believed that the influx of “people of other breeds” was the main cause “for the deterioration of American government” and that “there is not one in a thousand from Naples or Sicily that is not a burden on America.”

Their nostrums found a warm reception in Congress among such acolytes as Republican Senator David Reed of Pennsylvania, who gave his name to the National Origins legislation of 1924, and Democratic Senator Robert Reynolds of North Carolina, who fought to enforce it a decade later. Then there is the isolationist renegade Democratic senator, Burton Wheeler of Montana, and his Republican counterpart Gerald Nye of North Dakota; the Mississippi trio of the arch-segregationist Senator Theodore Bilbo and Senator James Eastland, “the voice of the white South,” together with the white supremacist congressman John Rankin, and Senator Strom Thurmond of South Carolina who led the Dixiecrat revolt against the Democrats in 1948. It was they and their ilk who adapted and refined Senator Lodge’s anti-immigrant literacy tests to keep black voters disenfranchised.

Earlier on, there had been the Democratic Senator “Pitchfork Ben” Tillman of South Carolina, and his rabble-rousing denunciation of the black man’s rights together with his nativist cry of “America for Americans”; the condescending white-supremacist bombast of Theodore Roosevelt; the fiat of Woodrow Wilson—at heart a Southern Democrat for all his progressive airs—that drove blacks from federal jobs together with his support of the Alien and Sedition Act abetting the deportation of political dissidents; the vote of Republican-controlled congresses under Presidents Warren Harding and Calvin Coolidge to institute ethnic quotas on immigration in the early 1920’s, further tightened in 1931 under President Herbert Hoover. While not intended as such at the outset, these restrictions, upheld by Congress with wide public support, became a death sentence by decade’s end for thousands of Jews attempting to flee the Nazis. Their plight provided a litmus test of where America stood during those fraught times and is particularly instructive regarding the frenzy of nativism against a newer generation of immigrants in our own era.

The moral opposition to this behavior, often on the defensive, was to be found mostly in liberal circles. In a reverse mirror, the cause of easing immigration quotas together with opposing Hitler had its most passionate supporters in the pages of such publications as The Nation, in the voices of advocates like the journalist Dorothy Thompson, in the appeals of prominent churchmen, and in Congress with such New York Democrats as Senator Robert Wagner and the congressmen Samuel Dickstein and Emanuel Celler. Their efforts generally foundered in the face of tenacious right-wing opposition.

After the war, the Renegade faction of the Democratic Party—together with its Southern contingent—persevered, most notably in the person of Senator Pat McCarren of Nevada, an anti-New Deal die-hard. McCarren’s seniority as a Democrat, together with his right-wing impulses, made him a thorn in the side of President Harry Truman. Although Truman signed the Displaced Persons Act of 1948 that would ultimately allow more than 400,000 DP’s into the U.S. through 1952, McCarren, a friend of Franco and a passionate Red-baiter, was responsible for the 1952 act bearing his name that imposed even more rigid quota limits, further restricting U.S. entry to refugees even as American Intelligence agencies slipped in ex-Nazis through the back door.

The year 1964 was a milestone on America’s road to polarization as the Tonkin Gulf Resolution formally sanctioned our massive commitment to the Vietnam conflict, a political wound from which the country has never fully healed. This was also the advent of the various activist movements of feminists, gays and other marginalized groups following on the heels of the Civil Rights era and its legislative victories of 1964-65. Conservatives, fighting tooth and nail against these advances, eventually coalesced around battling abortion, equal rights for same sex couples and voting rights.

But flying mostly under the partisan radar was the Hart-Celler Act, passed in 1965, that abolished the 1924 quota system and instead based immigration on reuniting families and attracting skilled labor. Originally intended to restore families of European extraction, the legislation soon attracted a wave of Asian newcomers followed by an influx of African, Caribbean and Latino immigrants, many of them from Mexico. The recession of the 1990s led to a resurgence of anti-immigrant sentiment, exacerbated after 9/11 by concerns over national security and a porous border. This became fodder for demagogues to prey on feelings of fear and economic dislocation, a combustible mix that awaited only a leader.

The game-changer was the election in 2008 of America’s first black president, Barack Obama, which galvanized the Tea Party movement in reaction to both Obama’s policies and his person. The tenure of a black man in the White House succeeded by a rabble-rouser who made his political mark fanning the flames of the mendacious “birther” movement, encapsulates the recurring narrative of a nation whose windows of progress are too often shuttered by subsequent regression.

The forces of reaction coalesced around a Tea Party Caucus that grew ever more strident in its opposition to Obama, while in the ensuing years it simultaneously purged the GOP of moderates who dwindled by attrition in a party where they were no longer welcome. Gatekeepers, who traditionally sought a national consensus candidate, were swept aside in the circus of the primaries, the turbulence of social media and the triumph of a celebrity culture that enabled a creature of the tabloids and television who thrived on bombast to drive all opposition before him.

In the past, such outsider challenges ran aground on the shoals of marginal appeal or regional limits. But now, the floodgates had been opened so that a fringe constituency commandeered what had once been the center. The drumbeat of demographic demise during this decade reached a crescendo producing an emotional impact on a religious right that saw its values threatened, together with a blue-collar constituency that felt its status diminished under the impact of globalization, technology and immigration. Trump didn’t have to take over the Republican Party. It had been primed and waiting for him.

Whether an opportunist, a racist or a bit of both, Trump saw his chance and turned the resentments of his aggrieved followers into political pay dirt, seizing on the grievances of a right-leaning rank-and-file who’d felt taken for granted by a Republican leadership that patronized it during elections and ignored it afterwards. Its efforts at forming a third party under figures like George Wallace and Ross Perot had come to naught. So it used Trump, the outsider, to take over one of the two major American parties. It is why this cohort will never abandon him. And why he will always do its bidding.

In truth, Donald Trump’s base has always been there. They are not conservatives, who would preserve what’s best in America while adapting to change. Rather, they are reactionaries who wish to turn the clock back to a half-imagined past when they and their kind enjoyed unquestioned status and unlimited power. In our lifetimes, they had often bet on the wrong horse who somehow fell short or disappointed them. Now their time, and their man, has arrived. No wonder some of them consider Trump a savior.

It will be up to the rest of us to see whether this creature slouching toward Bethlehem carries them, along with the rest of us, to a dark Jerusalem.