This article was originally posted at Huffington Post.

Early in this sordid and salacious campaign season, Republican presidential candidate Donald Trump derided Mitt Romney for losing his 2012 presidential bid against Barack Obama with these words: “He choked like a dog.”

But the choking dog today has orange hair. Nominated by the party of Lincoln, the Great Emancipator, Trump ranks among the most morally and emotionally unfit candidates for president in the history of the republic. This choking dog has, in fact, been choking since the day he announced his candidacy: coughing up the bile of nativism, racism, misogyny, and all the rest. Meanwhile, he has a risible counterpart in his Democratic opponent, Hillary Clinton. As the leaked Clinton emails reveal, she and her party have substituted Trump’s vilification of immigrants with the demonization of conservative Christians. Trump’s disregard for the basic rules of civility is mirrored by Clinton’s contempt for the constitution and the rule of law. His ignorance of America’s national security interests is matched by her indifference to national security in the pursuit of wealth and political power.

America is in the throes of a leadership crisis. It is, at its heart, a religious and cultural crisis—yet those leaders who should understand this fact and face it squarely seem to have escaped into another reality. Conservative commentators and think tanks have embraced Trump almost as a messianic figure who will “blow up the system” and give them privileged seats at the new table. Some have compared him to Ronald Reagan, others have hailed him as “the Winston Churchill of our time.” Many conservative Christians support Trump as “the lesser of two evils,” fearing that a Clinton victory means the “end of democracy, period.” Others accuse fellow Christians of moral cowardice for refusing to get on the Trump train, even likening them to Christians in Nazi Germany who failed to take a stand against Hitler.

Conservatives sully their cause, however, when they ignore history—or reach for it like a club to bludgeon and emotionally browbeat their critics. “A man who has lived in many places is not likely to be deceived by the local errors of his native village,” wrote C.S. Lewis. “The scholar has lived in many times and is therefore in some degree immune from the great cataract of nonsense that pours from the press and the microphone of his own age.”

We have endured a great cataract of nonsense during this campaign, from Christians as well as the secular-minded. Partisans on both sides have defended the indefensible—and have done so with a breathtaking degree of condescension, dogmatism, and intellectual dishonesty. Part of Lewis’s remedy for the phony moralizing of his age was a deep appreciation for history: an honest understanding of our civilization, with all of its faults, follies, and achievements.

Yes, America appears to be in the grip of a political and cultural crisis—no matter who wins this presidential election. But the United States has survived much darker days than these.

Conservatives who rightly worry about the composition of the Supreme Court, or the abuse of executive power, or a deepening racial divide, or the threat of terrorists slipping in among a refugee population ought to reflect on America in the 1930s and early 1940s. Back then, a liberal, Democratic president, Franklin Roosevelt, tried to subvert the constitution by stacking the Supreme Court with hand-picked nominees who would approve his “New Deal” legislation. He was substantially rebuked. As for racism, in the name of “national security,” the same liberal Democratic president ordered the forced “internment” of tens of thousands of Japanese-American citizens. Families were torn apart, lives ruined. The policy was eventually abandoned and repudiated. (Racism directed at African-Americans, of course, continued apace, as they were denied their civil rights and legally segregated from virtually all white establishments.) As for the immigration debate, throughout the 1930s neither Franklin Roosevelt nor Congress lifted a finger to help German Jews escape the fires of Nazism and find sanctuary in the United States. One of the reasons: the association of European Jews with Soviet Bolshevism, the great ideological enemy of the democratic West. We rightly look back on that lurch into nativism with sorrow and regret. Yes, to borrow the words of W.H. Auden, “it was a low, dishonest decade.”

It has been a low and dishonest presidential campaign—perhaps the lowest in our history. To borrow Trump’s words, both candidates are choking like a dog: eviscerating, that is, our public standards of decency, truth-telling, and integrity. In this, they are aided by a roster of sycophantic media, crony capitalists, and political hacks.

Can the United States endure under a Trump or Clinton regime? Yes, but history suggests that there will be a cost involved. We cannot fully anticipate the damage that either will inflict to our democracy, or to America’s democratic influence in the world. So what are people of faith, or of otherwise good conscience, to do? History and common sense tell us that we are not morally obligated to validate either candidate with our vote. An affirmative vote for either one makes it more likely that we shall see more of their kind—more leaders who incarnate political corruption, more demagogues who inflame our fears and resentments.

America can survive a Trump or a Clinton, but not a succession of Trumps and Clintons. To paraphrase a verse from the Book of Proverbs: “As a choking dog returns to his vomit, so a fool repeats his folly.” Leave the sad creature alone, walk away, and give him no aid.

Joseph Loconte is an associate professor of history at the King’s College in New York City and the author of A Hobbit, a Wardrobe, and a Great War: How J.R.R. Tolkien and C.S. Lewis Rediscovered Faith, Friendship, and Heroism in the Cataclysm of 1914-1918.