DENVER (AP) — The effort to ban former President Donald Trump from the ballot under the Constitution's "insurrection clause" turned to distant history on Wednesday, when a law professor testified about how the post-Civil War provision was indeed intended to apply to presidential candidates.

Gerard Magliocca, of Indiana University, said there was scant scholarship on Section Three of the 14th Amendment when he began researching it in late 2020, but said he uncovered evidence in 150-year-old court rulings, congressional testimony and presidential executive orders that it applied to presidents and to those who simply encouraged an insurrection rather than physically participated in one.

Magliocca didn't mention Trump by name, but the plaintiffs in the case have argued that Colorado must ban him from the ballot because his role in the Jan. 6, 2021, assault on the U.S. Capitol, which was intended to halt Congress' certification of Joe Biden's win and keep Trump in power, falls under the provision. The section originally was designed to prevent former Confederates from returning to their old federal and state jobs and taking over the government.

"It was not intended as punishment," Magliocca said of the ban. "A number of senators discussed the fact that this was simply adding another qualification to office."

Trump's attorneys on Wednesday moved for an immediate verdict dismissing the case because the plaintiffs didn't prove that Trump "incited" the Jan. 6 riot, saying all his action was legal speech. The judge said she would rule on the motion later in the afternoon.

Trump's attorneys have condemned the lawsuit as "anti-democratic" and warned that using an obscure provision to disqualify the Republican front-runner would be antithetical to the traditions of the world's oldest democracy. On Tuesday night, Trump slammed the Colorado proceedings in a video posted to his social media site, Truth Social.

"A fake trial is currently taking place to try and illegally remove my name from the ballot," Trump said.

In a reference to President Joe Biden, he added: "If crooked Joe and the Democrats get away with removing my name from the ballot, then there will never be a free election in America again. We will have become a dictatorship where your president is chosen for you. You will no longer have a vote, or certainly won't have a meaningful vote."

The Colorado lawsuit and a parallel case being heard Thursday by the Minnesota Supreme Court were organized by two separate liberal organizations, and the Trump campaign has alleged they're plots by Democrats to short-circuit the 2024 election.

It's likely the U.S. Supreme Court will have the final word on the issue. The nation's highest court has never ruled on Section Three, which was almost exclusively used during between 1868 and 1872, when Congress granted amnesty to many former Confederates who had previously been barred by it.

That section bars anyone from Congress, the military, and federal and state offices if they previously took an oath to support the Constitution and "have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof." It does not specifically name the office of president, but instead reads "elector of president and vice president."

The Colorado case raises issues that have rarely, if ever, been aired in courtrooms before the Jan. 6 attack: Does Congress need to create a mechanism to implement the ban? Does it apply to the presidency, especially since an earlier draft specified that office, but then it was removed? What constitutes an "insurrection" under its definition?

There's been an explosion of legal scholarship in recent months trying to figure that out. Going through dictionaries and court rulings from the mid-19th-century, Magliocca contended that the ban was implemented even without any congressional procedure, that senators noted it applied to the president and that the definition of an insurrection was simply a large-scale effort to impede the execution of laws.

Critics have warned that, if the provision is used to bar Trump, that could open the door to other, more conventional politicians getting banned for activities such as supporting protests against police brutality or other forms of civil disobedience.

Legal scholars believe the measure was cited just once in the 20th century, as justification for Congress not seating an anti-war socialist elected after World War I. The group behind the Colorado litigation, Citizens for Reforming Ethics in Washington, successfully used it to bar a rural county commissioner in New Mexico from office after he was convicted in federal court of a misdemeanor for entering the Capitol grounds during the attack.

The other liberal group behind the Minnesota challenge cited the Section Three provision in challenging the candidacies of Republican Reps. Marjorie Taylor-Greene of Georgia and Madison Cawthorn of North Carolina in 2022. The case against Taylor-Greene failed; Cawthorn's became moot after he lost his primary.

Trump's attorneys were expected to start their case Wednesday afternoon. They said it will include testimony that the former president tried to prevent violence on Jan. 6 and that of another law professor who will testify that Section Three should not apply to Trump.