In 1991, television personality Pat Buchanan launched his first campaign for president. Twenty-five years later, he won.

"We will put America first," Buchanan said in 1991. The previous year, he penned an essay for the National Interest titled "America First — and Second, and Third."

As a presidential candidate in 2016, Donald Trump gave a speech at the Center for the National Interest in which he asserted, "America First will be the major and overriding theme of my administration."

When Buchanan challenged President George H.W. Bush for the Republican nomination, he repulsed mainstream conservatives. William Bennett warned that Buchanan "cannot be allowed to hijack conservatism." Newt Gingrich said that Buchanan was "an extremist who is closer to David Duke than he is to the normal mainstream conservative." Several years later, in a 1999 article for National Review titled "A Conservative No More," Ramesh Ponnuru excommunicated Buchanan from the conservative movement.

Buchanan's brand of populist-nationalism is no longer marginal on the right. It is ascendant. A year after National Review released its "Against Trump" issue, it ran a cover story making the case for nationalism. Tucker Carlson discarded his libertarianism in favor of right-wing nanny-statism. Bennett, who accused Buchanan of "flirting with fascism," supports Trump, who quoted Benito Mussolini, the founder of fascism, approvingly ("it's a very good quote"). So does Gingrich. And David Duke.

Trump made this state of affairs possible, and Buchanan made Trump possible. Just as Barry Goldwater's defeat in 1964 precipitated Ronald Reagan's victory in 1980, Buchanan's presidential campaigns — in 1992, 1996, and 2000 — laid the groundwork for Trump's presidency. His candidacies exposed fissures on the right and showed that there was an untapped market for nativism, protectionism, and isolationism.

So why didn't Buchanan win then? His misfortune was that he ran in the 1990s, a decade of peace and prosperity, and campaigning on anger and resentment is hard in good times. But good times don't last forever.

At the end of the 20th century, conservatives faced a world without the Soviet Union. With communism defeated, Buchanan found new enemies: immigrants, multinational corporations, and "globalists" (among others). In the new culture war, Buchanan sided with "forgotten Americans" and "conservatives of the heart" (as opposed to the mind). At the 1992 Republican National Convention, he praised "hard, tough men" who "don't read Adam Smith or Edmund Burke." Men like Trump, who loves the poorly educated and doesn't even read his own books.

Buchanan criticized "democratist ideology" and "democracy worship" and yearned for an "American Caesar." Trump might not be as up to speed as Buchanan on Roman history, but he has shown Caesarian disdain for democratic institutions. On Tuesday, he said that Article II of the Constitution gives him "the right to do whatever I want," proving that he's both illiberal and illiterate.

Buchanan fretted about the paucity of "white Christians" and "non-Jewish whites" in the Ivy League and demanded affirmative action for "European-Americans." Trump signed an executive order aimed at protecting conservatives on college campuses.

Both have described immigration as an "invasion." To stop it, Buchanan proposed a "double-link security fence." Trump proposed a wall.

Both men are obsessed with American decline. Buchanan is the author of such ominous books as The Death of the West and Suicide of a Superpower, Trump of Crippled America. "The America we knew and grew up with, it's gone," Buchanan said in 2017. In his inaugural address, Trump talked about "American carnage" and "rusted-out factories scattered like tombstones," prompting George W. Bush to comment afterward, "That was some weird shit."

Buchanan said that Martin Luther King Jr. was "evil" and proclaimed "God bless Arizona" after the state refused to adopt King's birthday as a state holiday. As you may know, Trump has said racist-sounding things, too. After Trump told four nonwhite Democratic congresswomen to "go back" to "the totally broken and crime infested places from which they came," Democrats accused him of racism. "I don't have a Racist bone in my body!" Trump tweeted, absolving himself of bone bigotry.

Like Trump, Buchanan has been accused of racism — by Trump. In 1999, Trump said that Buchanan was "in love with Adolf Hitler." Asked about Buchanan on Meet the Press, Trump said, "He's a Hitler lover. I guess he's an anti-Semite. He doesn't like the blacks. He doesn't like the gays. It's just incredible that anybody could embrace this guy. And maybe he'll get 4 or 5 percent of the vote and it'll be a really staunch right wacko vote."

Trump later apologized to Buchanan. Not only did Buchanan forgive him, but he cheered him on. "I was elated, delighted that Trump picked up on the exact issues on which I challenged Bush," Buchanan told Politico.

When Trump decided to run for president in 2015, he was a reality TV star and a birther — a nuttier, more abrasive version of Buchanan. Whether he was calling for tariffs or assailing Mexican rapists, he talked like someone in the 19th century, not the 21st.

For all their similarities, Trump lacks Buchanan's intelligence and convictions. A know-nothing nativist, he espouses Buchanan's ideas without comprehending them. It's only a matter of time until Trump tells Native Americans to go back to their own country.