Eighty years ago, hundreds of Americans traveled to Berlin to attend the Summer Olympics.
The Nazis passed the infamous Nuremberg Laws a year earlier, which denied German Jews basic rights of citizenship.
The Dachau concentration camp had already started incarcerating homosexuals, immigrants and other opponents of the Nazis.
These acts of hatred, accompanied by ubiquitous racist and militarist rhetoric, were central to the behavior of the Nazi Olympic hosts, and everyone could see that.
And yet, American and other international athletes participated in the games, attending countless rallies with Nazi flags and straight-arm salutes all around them. Some joined enthusiastically in the white supremacist spectacle.
For his part, Adolf Hitler basked in the glory of his Olympic Games. He gained recognition as a world statesman for hosting such an impressive show of athleticism, power and modernity.
The presence of representatives from almost every country made the Nazis respectable.
“I look back to the 1936 Games,” Secretary of State Cyrus Vance, a former Olympic athlete, said more than 40 years later. “I think in hindsight that it was a mistake for us to attend.”
And Vance was right.
Historians have noted that the Nazi regime came out of the games with newfound confidence in its violent mission and a conviction that “world opinion” was on its side.
Very much like the Olympics, modern political conventions in the United States are public spectacles, staged for mass audiences.
The Republicans meeting in Cleveland will seek to put on a show of unity and strength for their presidential nominee, Donald Trump.
He will claim respectability as a successor to other great Republican leaders: Abraham Lincoln, Theodore Roosevelt, Dwight Eisenhower and Ronald Reagan.
Trump’s racism, anti-Semitism, misogyny and bullying will not be contained, but rather justified and enabled by those in the crowd.
He will look powerful, popular and self-righteous.
Trump will claim his views are normal, his behavior acceptable, and his fascism part of the American way. The show will make these claims more convincing, and everyone in the audience will be complicit.
Democracy depends on people taking moral stands, declaring certain behavior unacceptable. Otherwise, democratic procedures descend from deliberation into violence, as we have seen across the nation in recent days.
The vast majority of Americans — Republican, Democrat and independent — who oppose racism, anti-Semitism, misogyny and bullying must boycott and speak out against the Trump spectacle. They must stand against his claim to respectability.
As many Americans learned in 1936, there are times when neutrality or party loyalty are no longer enough to preserve basic democratic principles.
Standing silently by as the worst of the rhetoric is spewed just enables more of the same. There is a moral assent in the cowardice and careerism of those who know better, but choose not to speak.
The responsibility rests squarely with Republicans who can still recover the moral center of their party that sits on the edge of a hateful abyss.
Jeremi Suri holds the Mack Brown Distinguished Chair for Leadership in Global Affairs at The University of Texas at Austin.