With the NAACP as counsel, Rep. Bennie Thompson (D-Miss.) on Tuesday sued the former president, his lawyer Rudolph W. Giuliani, the Proud Boys and the Oath Keepers, accusing them of conspiring to stage the Capitol insurrection and violating a law known as the Ku Klux Klan Act. The complaint explains that the law, enacted in 1871, “was intended to protect against conspiracies, through violence and intimidation, that sought to prevent Members of Congress from discharging their official duties. The statute was enacted in response to violence and intimidation in which the Ku Klux Klan and other organizations were engaged during that time period.”

While removed in time, the KKK Act was designed for precisely the sort of conduct witnessed in the lead-up to Jan. 6, namely a campaign to disenfranchise millions of voters (disproportionately African American) and subvert the election.

The lawsuit reads a lot like the House impeachment managers’ case against the ex-president, detailing the Big Lie that the election was stolen and the disgraced former president’s incitement of the mob. The complaint alleges, “Having delayed delivering his incendiary remarks to the crowd at the Ellipse in order to afford the Defendant Proud Boys an opportunity to arrive at the Capitol and overcome its initial defenses, Defendant Trump acted in concert with the Proud Boys, allowing them to clear the way for the arriving riotous crowd to descend on, and ultimately enter, the Capitol.”

The complaint also details the former president’s refusal to call off the mob. It reads, “Soon after members of the riotous crowd dispatched by Defendants Trump and Giuliani forcibly entered the Capitol and began roaming its halls and offices, Defendant Trump called upon them to disrupt the Electoral College ballot count, tweeting that ‘Mike Pence didn’t have the courage to do what should have been done.’” It also recounts that Giuliani, “while the insurrection was ongoing,” urged Sen. Tommy Tuberville (R-Ala.) in a voice message to “object to numerous states and raise issues so that we get ourselves into tomorrow ideally until the end of tomorrow.”

Thompson’s complaint concludes: “As a result of the acts set out in the above paragraphs committed in furtherance of this conspiracy, Plaintiff Thompson was hindered and impeded in the discharge of his official duties and suffered the deprivation of his right to be free from intimidation and threats in the discharge of his official duties, as explicitly protected under Ku Klux Klan Act.” In addition, “when the Capitol was under attack, Plaintiff Thompson suffered emotional distress.”

And in a deft touch, the complaint quotes Senate Minority Leader Mitch McConnell's (R-Ky.) speech after he voted to acquit the ex-president on Saturday:

There is no question that President Trump is practically and morally responsible for provoking the events of that day. The people who stormed this building believed they were acting on the wishes and instructions of their president. And their having that belief was a foreseeable consequence of the growing crescendo of false statements, conspiracy theories, and reckless hyperbole which the defeated President kept shouting into the largest megaphone on planet Earth.

Marc Elias, who successfully beat the former president’s lawyers in court over 60 times, told me, “It is great to see the NAACP and Congressman Thompson suing Trump. If we want to protect our democracy, we must make clear that sedition has consequences.”

This and any subsequent suits will face the argument that a president cannot be sued for acts done in official capacity. Plaintiffs, however, have a compelling retort. As lawyer Thomas Geoghegan wrote for The Post in January: “It’s true that the president has absolute immunity from civil damages arising from his official acts, but as the Supreme Court made clear last July in Trump v. Vance, rejecting Trump’s claim of absolute immunity from a New York district attorney’s subpoena, there is no such immunity for nonofficial acts. In Nixon v. Fitzgerald, the 1982 case in which the court announced the principle of ‘absolute’ presidential immunity, the court said it covered acts within the ‘outer perimeter’ of the president’s office — but presumably not outside of it.” There is an awfully strong case to be made that Trump’s inciting speech was about as far outside a president’s “official duties” as one can get. It was a breach of his oath and failure to perform his duties, landing him in a second impeachment trial.

The civil lawsuit, I am certain, is the first of many from possible plaintiffs — those injured, the families of those killed, the city of Washington, D.C., for expenses incurred, those traumatized inside the building and members of the D.C. and Capitol police forces who were pressed into combat. Think also of the Georgia officials who might also bring lawsuits against the former president and Sen. Lindsey O. Graham (R-S.C.) for trying to disqualify legal votes and reverse the election’s outcome. Michigan state officials who were pressured to do the president’s bidding and called to the White House might have claims as well.

Thompson’s lawsuit underscores several points to keep in mind moving forward.

First, the education of the American people will go on for months and possibly years, as civil litigation and possible criminal cases wind their ways through the court system.

Second, the cost of the defense may well bankrupt groups such as the Proud Boys and the Oath Keepers; that’s the point. It may also put a considerable financial burden on Giuliani and even his client, who seems to have difficulty finding competent counsel. “One advantage of civil enforcement is the standard of proof of preponderance of the evidence instead of guilt beyond a reasonable doubt,” former prosecutor Barbara McQuade told me. “Civil enforcement was used to hold O.J. Simpson accountable when criminal enforcement fell short. Although the penalty is money damages and not imprisonment, for some defendants, that punishment hurts them more than any prison time could.”

Third, civil suits provide for discovery — documents and live testimony from third parties can be required. The former president may be forced to testify under penalty of perjury (unless he invokes his Fifth Amendment rights). John Paredes, counsel at Protect Democracy, observed that "if discovery here — or in any other congressional or judicial proceeding for that matter — turns up evidence that certain individuals knew that there would be a storming of the Capitol but didn’t take any action to prevent it from happening, they too may soon find themselves called to account for their actions in federal court.”

No doubt, there are a host of attorneys delighted to take up cases against the former president and his accomplices pro bono or on a contingency. We may see a cottage industry of such lawsuits related to the Jan. 6 attack. It may prove to be an extremely effective way to hold the former president accountable.

Early on Jan. 6, The Post's Kate Woodsome saw signs of violence hours before thousands of President Trump's loyalists besieged the Capitol. (Joy Yi, Kate Woodsome/The Washington Post)

Read more: