In the American political system, parties have a certain "circuit breaker" role to play. Seven years ago, the Republican National Committee withdrew support from Senate candidate Todd Akin of Missouri after he tried to distinguish between "legitimate rape" and a different kind of rape. That stance probably cost the Republicans a seat in the U.S. Senate, but it put the party on record for being on the side of decency.

In 1991, David Duke, a former grand wizard of the Ku Klux Klan, placed second in the Louisiana open primary for governor. President George H.W. Bush denounced Duke, saying that he "has a long record, an ugly record of racism and of bigotry. ... I believe he should be rejected for what he is and what he stands for." Former Louisiana Republican governor David Treen led an effort funded by the Republican Governors Association against Duke, who went on to lose to Democrat Edwin Edwards. That gave the seat to a Democrat, but it put the Republican Party on the right side of the fight against racism.

How different it is today. In 2016, presidential candidate Donald Trump called for "a total and complete shutdown of Muslims entering the United States until our country's representatives can figure out what the hell is going on." It was a clear violation of the Constitution's Article VI protections against religious tests, but the Republican Party did nothing.

RNC Chairman Reince Priebus, who had previously led an extensive analysis of the need for the party to expand its appeal beyond white Christian voters, refused to commit the party to support the Constitution. Later, when Priebus served as White House chief of staff, President Trump seemed to take particular delight in humiliating him, reportedly tasking him with killing flies. Trump had learned that Priebus, like the party he once led, was weak and worthy of his disgust.

In 2017, the RNC and Trump endorsed Alabama Senate candidate Roy Moore, who, in addition to being an accused child molester, had a troubled history on race.

Now, in the 2020 campaign season, Trump has embraced open racism like no president since Andrew Johnson. In the heart of the old Confederacy, Trump stood before a rally of North Carolinians on Wednesday and denounced four women of color in Congress, inspiring a "send them back" chant that delighted the crowd. (He disavowed the chant on Thursday.) He keeps presenting the country with uncomfortable moral tests. The Republican Party keeps failing them.

Southerners like me know the game Trump is playing. We have seen it, sadly, time and again. Trump is the rightful heir to Lester Maddox's ax handles and George Wallace standing in the schoolhouse door. What's next for the RNC? Hang a Confederate battle flag in front of the national headquarters?

It is difficult to express how much this hurts my heart. To those of us who had believed and worked for the "compassionate conservative" vision of George W. Bush, watching the Republican Party embrace an open racist is like seeing an old friend drink himself to death. Lord knows we weren't perfect, but at least we aspired to be something bigger and better than Trump's bitter ugliness.

It's a disgrace and a political disaster. In 1956, Dwight Eisenhower won 39% of the African American vote. Eight years later, Barry Goldwater opposed the Civil Rights Act and that figure plummeted to 7%; African American voters have never returned to the party.

While every year the United States becomes less white, the Republican Party has abandoned any pretense of being the Big Tent Party. Perhaps Trump can win with this message in 2020, but this embrace of racism by a major American political party will rightly hang over the GOP in a shroud of shame. African American voters did not forget 1964, and there is little chance that nonwhite voters will forget 2020.

The Republican Party must decide if it is defined by Trump's prejudices or the principles it has long claimed to believe. Is it too late to hope that it can summon courage and stand for more than Trump's re-election? Probably. But if the party denounced Trump's bigotry and hate, even at a short-term cost at the 2020 ballot box, it could be a turning point with long-term gains. A wise politician once told me: Be for the future. It's going to happen anyway.

As Alabama governor, George Wallace actually did a lot of good things, such as passing the law for free school textbooks. But no one is remembered as the "free textbook" Wallace supporter. So it is with this moment. And none of the current Republicans will be remembered as a "tax reform" Trump supporter. None of the policies or judges will be remembered, but this open racism will never be forgotten. Trump long ago made his choices. The question for Republicans is simple: What choice will you make?

Stevens is a writer and Republican political consultant.