In his address to the Republican convention on Tuesday night, House Speaker Paul Ryan accused Democrats of inciting ethnic resentment. “Let the other party go on and on with its constant dividing up of people, always playing one group against the other, as if group identity were everything,” Ryan charged. “In America, aren’t we all supposed to see beyond class, see beyond ethnicity? Are all these lines drawn to set us apart and lock us into groups?”

It was a remarkable sermon, delivered on behalf of the most egregious racist nominated to the presidency by a major party in at least half a century. Ryan spoke every word with his usual earnestness, unencumbered by shame. Looking back at history, we tend to focus on villains, men like Donald Trump who use hatred to gain power. We forget the importance of cowards. Every Trump needs his Ryan.

I’ve always liked Paul Ryan. He talks about opportunity and empowerment, not scapegoats. He focuses on fiscal responsibility and self-reliance, two of my favorite Republican themes. He strikes me as constructive and sincere. It’s not his fault that the Republican Party, during his tenure as speaker, nominated Trump.

But Trump’s nomination confronted Ryan with a terrible dilemma. As the head of the Republican Party, Ryan had to decide whether to reject Trump and lose the election, or embrace Trump and lose the party’s soul, as well as his own. Ryan made the wrong choice. He decided that the Republican Party would criticize race baiters, but it would also tolerate and support them.

Trump has run the most racially incendiary campaign in decades. He has proposed to bar all Muslims from entering the United States. He has explicitly attacked the trustworthiness of Mexican Americans, Cuban Americans, and Seventh-day Adventists. He has libeled Arab Americans, mocked Native Americans, retweeted anti-Semites, and argued that a sportscaster shouldn’t have apologized for anti-black comments. Today, no decent, well-informed person can honestly deny Trump’s penchant for prejudice.

During the primaries, Ryan condemned Trump’s Muslim ban and his failure to forcefully repudiate former Klansman David Duke. So did Mitt Romney, the former Massachusetts governor who, as the GOP’s presidential nominee, had put Ryan on the Republican ticket in 2012. But the Republican voters of 2016 flocked to Trump, and on May 3, the chairman of the Republican National Committee declared him the party’s presumptive nominee. Republican politicians had to decide: Could they support a racist demagogue for president?

Romney decided he couldn’t. “Our first priority should be to stand by our principles,” he told the Wall Street Journal. “If those are in conflict with the nominee, the principles come first.”

In an interview with CNN on June 10, Romney outlined three reasons to oppose Trump. First, racism is morally non-negotiable. It’s a deal-killer. “I simply can’t put my name down as someone who voted for principles that suggest racism or xenophobia, misogyny, bigotry,” said Romney. “If there’s someone that was an anti-Semite, for instance, and they had all of the same positions I had, and they were running for president, I simply could not vote for them.”

Second, Romney saw racism as a character issue and Trump’s deployment of it as a deep flaw, not the kind of thing consultants or speechwriters could fix. “He can change his rhetoric. I believe he can hide who he is,” Romney conceded. “But I believe that who he is has been revealed by his lifetime and by the words in the campaign that he has spoken.”

Third, Romney worried about Trump’s cultural effects. “I don’t want to see trickle-down racism,” said Romney. “Presidents have an impact on the nature of our nation. And trickle-down racism, trickle-down bigotry, trickle-down misogyny—all these things are extraordinarily dangerous to the heart and character of America.” Essentially, Romney was challenging his party to see prejudice in a new way—to treat it as an issue of national moral health, as Republicans have traditionally done with abortion and marriage.

Initially, Ryan, too, withheld his endorsement. On May 5, two days after Trump was anointed, Ryan said he wasn’t ready to support the presumptive nominee. “This is the party of Lincoln, of Reagan, of Jack Kemp,” said Ryan. “What a lot of Republicans want to see is that we have a standard-bearer that bears our standards.” A week later, after meeting with Trump, Ryan drew a distinction between “policy disputes,” on which Republicans could agree to disagree, and “core principles,” which were non-negotiable.

Did race-baiting violate Ryan’s core principles? For two weeks, Ryan kept his silence, and Trump held his tongue. Then, at a rally on May 27, Trump unleashed a 10-minute tirade against Gonzalo Curiel, the judge presiding over a fraud case against Trump University. Trump pronounced the judge’s name for effect, eliciting boos, and informed the crowd that Curiel—who had been born in Indiana—“happens to be, we believe, Mexican.” Trump’s spokeswoman followed up, asserting in a CNN interview on May 30 that Curiel was “connected” to protesters who brandished “Mexican flags” and were trying “to stop an American president from running for office.”

Trump’s attack on Curiel sparked a national uproar. Ryan couldn’t have missed it. But three days later, on June 2, he endorsed Trump. In an op-ed, Ryan said Trump had earned his blessing by affirming “fundamental principles such as the protection of life” and pledging to work with House Republicans on “the issues that make up our agenda.” Racism wasn’t on the list.

Hours after the op-ed appeared, Trump went after Curiel again. He said the judge’s “Mexican heritage” created “an inherent conflict of interest” that made him unfit to judge Trump, since Trump was “building a wall” on the Mexican border. Another uproar ensued. Ryan could have withdrawn his endorsement. But he didn’t.

Ryan, unlike Romney, didn’t see racism as a character issue. He treated Trump’s latest slur as a mysterious outburst. It “was out of left field, [to] my mind,” Ryan sputtered in a radio interview on June 3. “It’s reasoning I don’t relate to.” Sometimes, Ryan conceded, Trump “says and does things I don’t agree with.” But Ryan stuck with him, arguing that Trump would sign Republican bills into law.

Over the next two days, Trump repeated his attacks on Curiel’s ethnicity. On June 7, reporters asked Ryan whether he regretted endorsing Trump. Ryan called Trump’s remarks “the textbook definition of a racist comment,” but he refused to disown the presumptive nominee. “I don’t know what’s in his heart,” Ryan pleaded. In a radio interview on June 9, Ryan dismissed Trump’s racial jabs as “antics.”

Trump pressed on. After the Orlando massacre on June 12, he launched a weeklong campaign against “second-generation” Muslim Americans, those who had been born in the United States. He claimed that there was “no real assimilation” of Muslims and that they were “trying to take over our children” by telling kids “how wonderful Islam is.” Trump mocked Sen. Elizabeth Warren, calling her “Pocahontas.” He said sportscaster Jimmy “the Greek” Snyder shouldn’t have apologized for racist remarks about blacks. He tweeted an image of Hillary Clinton—originally circulated by anti-Semites—that framed her against a background of dollar bills, next to a six-pointed star with the words, “Most Corrupt Candidate Ever!”

Ryan shrugged off these incidents as unhelpful but meaningless and unrelated. He blamed the Star of David incident on a “flunky” and advised Trump to “clean up the way his new media works.” In a CNN town hall on July 12, when a questioner asked about perceptions of Republican bigotry, Ryan urged voters to focus on the party’s “ideas,” not “some of the harsh rhetoric you see here or there.” To Ryan, the racism of the party’s presidential nominee was a sideshow.

Ryan, like Romney, offered three arguments about race-baiting. But Ryan’s arguments weren’t for banishing it. They were for tolerating it. First, Ryan said it was unacceptable to divide the GOP. “If I lead a schism in our party, then I’m guaranteeing that a liberal progressive becomes president,” Ryan warned in a press conference on June 23. Three weeks later, at the CNN town hall, he shot down a questioner who asked about voting libertarian. That’s “basically voting for Hillary Clinton,” Ryan scoffed.

Second, Ryan argued that Republican leaders should yield to the will of Republican voters. In an interview that aired June 19 on Meet the Press, he declared that he had a “responsibility” not to “dis-unify our party and disrespect the voters, the Republican primary voters of America.” In the CNN town hall, Ryan said Trump “won the primary fair and square. And that is why we want to respect the will of these voters.”

Third, Ryan depicted religious bigotry as a negotiable issue and a tolerable point of view. In a June 12 interview on This Week, he emphasized that he and Trump saw eye to eye “on the big issues”: tax reform, welfare reform, and health care. When George Stephanopoulos asked about the Muslim ban, Ryan replied: “We don’t agree on that. That’s fine. Good people can disagree on things.” In the CNN town hall, Ryan again gave Trump a pass on the Muslim ban. “Look, no two people agree on everything,” he said.

These three arguments guarantee that the Republican Party, under Ryan, will accept bigots. They might be criticized or chided, but not excluded, even from the top of the national ticket. To exclude them would divide the party. It would disrespect the Trump-friendly voters who now control the Republican nominating process. It would impose absolutist judgments on a party in which the taboo against ethnic and religious slurs has been set aside as just another form of “political correctness.”

Ryan’s job at the convention, and for the remainder of the election, is to pretend that none of this has happened. So he ended his speech Tuesday night with a plea for love.

“Everyone is equal,” he said. “Everyone has a place. No one is written off, because there is worth and goodness in every life. … That is the Republican ideal. And if we won’t defend it, who will?”

Indeed, who will? Not Paul Ryan. Not the party of Lincoln. Not anymore.

Read more Slate coverage of the 2016 campaign.