Supporters of President-elect Donald Trump cheer during an election rally on Nov. 9 in New York. (AP/ Evan Vucci)

Donald Trump’s election as president startled many Americans. A number of observers commented that Trump’s campaign represented a set of illiberal values and policy positions far outside of the United States’ political traditions of individual rights, equality and democracy.

But in many ways, Trump represents a return to the historical norm. Such classical liberal values have often not predominated in the United States. In fact, they have always logically competed against — while being politically intertwined with — a set of commitments to hierarchies of race, nationality and religion, among others. Indeed for much of American history, these illiberal values held sway.

The U.S. is emerging from an exceptional period of caution about race and ethnic nationalism

Since the 1940s, chastened by the example of Nazism and conscious of the U.S.’s modern global responsibilities, both major parties have avoided more overt racism and ethno-nationalism.

But the U.S. has always had at least one (and often more than one) major political party devoted to some notion of white nationalism. From its founding in the 1820s up until the 1940s, the Democratic Party was explicitly devoted to white supremacy, first supporting slavery and then Jim Crow.

Similarly, since the end of Radical Reconstruction, the Republicans (like their Whig predecessors) have advocated a variety of immigration restrictions for certain nationalities and religions — positions that the party increasingly stressed as part of its “Southern Strategy” of appealing to racial conservatives beginning in the 1960s. Trump emphasized these themes more explicitly during his campaign.

U.S. efforts toward racial equality have come during wars

As we have written, illiberal beliefs and practices have been so strong that the United States has usually only made significant progress toward racial equality only under the exigencies of war. For example, African American rights only advanced dramatically during three periods in U.S. history — during the Revolutionary War, the Civil War and immediately after, and most recently during World War II and the Cold War.

In each of these periods the United States was fighting a war against illiberal enemies, prompting it to highlight its own liberal values. In addition, each of these were big wars in which victory required African Americans as soldiers, sailors, defense workers, and at the very least, quiescent citizens. Finally, and perhaps most important, black and white civil rights advocates used wartime pressures to leverage for legal changes.

But for many white Americans, these advances were instrumental to the need to win the war and accepted only grudgingly. Wartime pressures for equality were felt most keenly at the elite level. Most ordinary white Americans were apathetic at best about such changes. Many were virulently opposed. Once the external pressures of war were removed, the elite consensus broke down, allowing various factions to encourage and harness these racial sentiments for their own political ends.

But the Cold War ended 20 years ago

These historical patterns help explain Trump’s election victory. After the Cold War ended with the fall of the Communist bloc in 1989, the United States no longer faced the external pressures that had pushed it toward greater egalitarianism. Moreover, rising levels of immigration combined with the 9/11 attacks moved many American in the direction of great ethnocentrism and nationalism. Furthermore, the rise of right-wing nationalist movements in Western Europe has provided inspiration and encouragement to similar movements in the United States.

Racial conservatives who had abandoned legal segregation began fiercely attacking measures designed to aid nonwhites. Nevertheless, the 1965 Immigration Act and 1965 Voting Rights Act combined to increase the political clout of nonwhites, making possible President Obama’s election in 2008.

Aside from these historical legacies, recent decades have seen little overall progress for African Americans relative to white Americans. In recent years, conservative Republicans have successfully litigated to weaken the Voting Rights Act, culminating in the Supreme Court’s 2013 decision in Shelby County v. Holder, which eliminated the federal government’s ability to review in advance changes in voting laws and regulations in historically discriminatory states. In response, many states have enacted restrictive voting laws that disproportionately exclude minority voters.

In the wake of these shifts, U.S. voting patterns have become even more racially polarized. Scholars like Michael Tesler, Christopher Parker and Matt Barreto, and Marisa Abrajano and Zoltan Hajnal have shown how Republicans and Democrats are increasingly polarized by attitudes on race and immigration. In turn, race has become one of the best predictors of partisan preferences.

To be sure, Trump appealed to many voters disgusted by gridlocked Washington elites and to those suffering economic stagnation. At the same time, he exploited and amplified these trends of racial, ethnic and religious polarization. He gained political prominence by denying the citizenship of the nation’s first African American President. He ignited his successful presidential campaign by denouncing Mexican and later Muslim immigrants.

Philip Klinkner’s research has found that racial resentment, antipathy to Muslims, and belief that Obama is a Muslim were much more important factors in explaining support for Trump over Hillary Clinton than were income or economic attitudes. As President, Trump will likely accelerate the transformation of the Republicans into the party of white nationalism, which for many of his evangelical supporters means specifically white Christian nationalism.

So now what?

What does this mean for the future of American politics? A number of alternative scenarios are possible. Here’s one: Trump presides over economic growth and some policies aiding white workers while avoiding catastrophic blunders. Meanwhile, Republicans continue to make it harder for nonwhites to vote. In this case, lightly perfumed white nationalism may predominate for years to come.

On the other hand, even some Republican-appointed judges have voided many of the most egregious vote suppression efforts. Demographic trends suggest that the U.S. may soon be a “majority minority” nation.

Perhaps such shifts will mean only continued deep and paralyzing national polarization.

But here’s another possible scenario. Advocates of an egalitarian multicultural society devise policies to help accommodate and assist those white Americans made anxious and angry by their perceived cultural and economic eclipse. Meanwhile, if Trump’s policies fail to improve the economic and cultural standing of those who voted for him, it’s possible that the plurality of U.S. voters who chose Clinton may be joined by enough others to select a different president and vision of the United States in 2020.

Philip A. Klinkner is the James S. Sherman Professor of Government at Hamilton College.

Rogers M. Smith is the Christopher H. Browne Distinguished Professor of Political Science and Associate Dean for Social Sciences at the University of Pennsylvania.