Last week, President Trump declined to commit to accepting the results of the election. When given a chance to commit to a peaceful transition of power, he said, “We’re going to have to see what happens.” On Thursday, he continued his months-long campaign to raise concerns about voter fraud linked to mail ballots — despite no evidence of it actually being an issue — claiming that short of a Supreme Court decision, the vote count would be a “a horror show.” Trump has even said things that some supporters might interpret as welcoming violence. All of this has raised possible scenarios about a potential constitutional crisis that could unfold in November.

The result could be a surge in violent white supremacy, designed to bolster Trump and extend his time in office. It has happened before in American history during the contested 1872 Louisiana gubernatorial election, between Conservative party candidate, ex-Confederate battalion commander John McEnery and Republican William Pitt Kellogg.

The election took place during Reconstruction when the federal government was working to guarantee civil rights of formerly enslaved people. After the Civil War, the 13th Amendment freed 4 million African-descended Americans. The Civil Rights Act of 1866 and 14th Amendment, ratified in 1868, guaranteed equal protection of the laws and struck down discriminatory Black Codes. The 15th Amendment guaranteed male citizens the right to vote regardless of race or previous slavery, and the 1870 Enforcement Act — also called the Ku Klux Klan Act — empowered federal authorities to prosecute civil rights violations.

In 10 years, the country had seemingly moved from Emancipation Proclamation to citizenship for African Americans. Yet conservative Whites rallied around a vision of bringing back the old order. The stakes were high in Louisiana’s 1872 election. It was the first to take place under the 1868 state constitution permitting Black voting in accordance with federal civil rights protections. It was a test of whether Republican-led efforts to bring African Americans into the party and build a multiracial political order could survive determined, armed White opposition.

McEnery waged a campaign rooted in white nationalism. During the campaign, he railed at carpetbaggers — Northerners who came South after the war — and vowed to “redeem” the state for those with whom he “stood shoulder to shoulder in many a hard fought field.” It was an appeal to elevate the Lost Cause and roll back the civil rights Black Louisianans had gained in the 1868 state constitution, along with federal protections.

His pro-Reconstruction opponent was controversial. Kellogg was a New England native and had been a Union cavalry commander in Illinois before Abraham Lincoln appointed him Louisiana customs collector, which springboarded him into Louisiana politics. Black citizens and business interests looking to rebuild Louisiana supported his candidacy while Kellogg’s outsider status and commitment to President Ulysses S. Grant’s Reconstruction agenda inflamed his political foes.

Troubles started for the Kellogg campaign well before the election. According to a report, McEnery allies ordered election supervisors “to impede in every possible manner the registration of colored voters, in such ways as closing their offices when large numbers of negroes were waiting for registration, alleging that they were out of [ballots] … removing their offices to remote points, notifying only White men of their location … [and] establishing polling places without due notice.” Election officials demanded voter ID in the form of birth certificates from men who had been born in slavery and therefore had none. All that was done for the explicit purpose of “obstructing the voting of Republicans, especially of colored men.”

After the election, both candidates declared victory, and refused to back down. It quickly became clear that the fix was in. Outgoing Gov. Henry Clay Warmoth, allied with McEnery, had taken control of the election through a Returning Board of his own appointees who declared McEnery the winner.

Kellogg’s supporters protested, and a federal court eventually certified Kellogg the winner. Warmoth was soon impeached, and Lt. Gov. P.B.S. Pinchback served 35 days as the first African American governor. And yet McEnery refused to concede and so, on Jan. 13, 1873, two separate ceremonies in New Orleans inaugurated McEnery and Kellogg. After both took office, they sent commissions to competing sets of parish officials to run local government. Both administrations acted like they were in charge, and Democrats even set up a rival legislature.

Officials with conflicting commissions fanned out over the state, playing havoc with local governance. Kellogg appointees recognizing one governor and one legislature showed up to battle McEnery appointees sent by another governor backed by another legislature, each claiming legitimacy.

Two rival judges and sheriffs wrestled for control of Grant Parish in north-central Louisiana. By March 1873, Kellogg-appointed Republican officials backed by a Black-led state militia regiment had taken control of the Colfax courthouse in Grant Parish. Democratic claimants to judge and sheriff — including Christopher Columbus Nash, who reported to McEnery — appealed to White supporters. Many were ex-Confederates who formed white supremacist paramilitary organizations.

On Easter Sunday, April 13, 1873, Nash led some 300 white insurgents who surrounded the courthouse and massacred over 150 Black residents. Police and federal forces arrived from New Orleans the following day to find bodies mutilated, burned and shot in ways suggesting executions. Others were recovered from the Red River, shot down as they fled.

Most of the perpetrators escaped. A determined U.S. attorney, James Beckwith, investigated, uncovering evidence that Nash and others orchestrated the massacre. It was a calculated political act. He brought charges against nine gunmen under the Ku Klux Klan Act of 1870. And yet, Beckwith only secured three federal convictions. Soon many perpetrators became Democratic officeholders, because their violent acts had boosted their political standing among Reconstruction’s opponents.

In the meantime, emboldened white paramilitaries terrorized Black Louisianans and their White supporters. In the summer of 1874, the White League formed as an open paramilitary organization supporting conservatives. Members perpetrated the Coushatta Massacre in Red River Parish in August, targeting Black officeholders and White supporters. That September, thousands of armed White League partisans supporting McEnery drove Kellogg into exile from New Orleans, and federal troops were finally called in to quell the violence and restore Kellogg’s government to office.

But then the Supreme Court intervened. In United States v. Cruikshank, the court overturned the convictions of three murderers from the Colfax massacre. Chief Justice Morrison Waite — a Republican appointee — ruled that the civil rights provisions of the 14th Amendment, including the equal protections of the laws and right to due process, did not apply to the victims of the Colfax massacre. Concurring, Justice Joseph Bradley — also a Republican appointee — found that none of the murderers were alleged to have “committed the acts complained of with a design to deprive the injured persons of their rights on account of their race, color, or previous condition of servitude.” The justices willfully ignored the killers’ political motivations, ruling that 14th Amendment applied only to states and not individuals — or, in this case, white supremacist militiamen. Federal civil rights protections soon became a dead letter.

McEnery did not originate the strategy of using violence to recover what he lost at the ballot box. But his willingness to mobilize white supremacist militants instead of abiding by the democratic process was a death knell for Reconstruction’s promise of equal rights. The state and country soon retreated from Reconstruction, and by the dawn of the 20th century, 90 percent of Black Louisiana voters were disenfranchised. His vision of citizenship as exclusive rather than inclusive, and his contempt for the democratic process and the opposition is a cautionary tale. Political violence once unleashed is difficult to restrain.