For more than an hour Tuesday, as the House debated whether to condemn President Trump’s racist tweets telling four minority congresswomen to “go back” to their “crime-infested” countries, the debate had to be put on pause. The problem: House Speaker Nancy Pelosi (D-Calif.) used the word “racist.”

“Every member of this institution, Democratic and Republican, should join us to condemn the president’s racist tweets,” she said. With that, her words triggered a long-standing precedent that you can’t call the president, or even his words, “racist” on the House floor. And from there a frenzy ensued.

Rep. Douglas A. Collins (R-Ga.) asked Pelosi whether she wanted to “rephrase that comment,” but she refused. So Collins asked that her words be “taken down” — struck from the record. Soon, the House rule-keepers were reviewing her remarks like NFL officials looking at a potentially game-changing moment on replay. The chairman presiding, Rep. Emanuel Cleaver II (D-Mo.), grew so frustrated by the disagreement that he dropped the gavel and said, “I abandon the chair.” Finally, about an hour later, the verdict was in: Pelosi was out of order, and her “words should not be used in debate,” ruled House Majority Leader Steny H. Hoyer (D-Md.).

And for that, Pelosi might as well have the King of England to thank.

In deciding that Pelosi’s language was out of line, Hoyer wasn’t merely pointing to a House rule book. The principle used to chastise Pelosi — that lawmakers can’t insult the president’s character — is rooted in the British Parliament’s rules of decorum that shaped the Founding Fathers’ understanding of how Congress should work, congressional scholars said.

As Josh Chafetz, a Cornell Law School professor, pointed out on Twitter, Hoyer’s ruling was based in precedent that can be found in Thomas Jefferson’s Manual of Parliamentary Practice. “In Parliament, to speak irreverently or seditiously against the King is against order,” the 1801 book reads.

Two centuries later, that’s still the law in Congress — at least whenever political opponents decide to enforce it.

“U. S. parliamentary process and the manual is rooted in British precedents to a large extent,” Eric Schickler, a political science professor at the University of California at Berkeley, told The Washington Post. “In Britain, it was out of order to speak in parliament to attack the king, to attack the crown directly.”

The House ultimately passed the resolution condemning Trump’s tweets. Pelosi was not the only Democrat to call Trump’s tweets racist, but she was the only one targeted by Republicans for impermissible language. Carried by Democrats, the House ultimately voted not to strike her words from the record, as well as to allow her to continue speaking; typically, the punishment would be to sit silently.

House rules don’t allow members to offend their colleagues’ “personalities,” or that of the president. But Jefferson’s manual is slightly different from the House rules, Schickler said. It’s more like a guide on how to interpret whether rules have been broken. In past decades, lawmakers have been slapped on the wrist for everything from calling President Ronald Reagan a “liar” to saying President Barack Obama was throwing a “little hissy fit.” Even quoting someone else’s disparaging remarks of the president has gotten lawmakers in trouble. Former congresswoman Cynthia McKinney (D-Ga.) was reminded to keep her language in check after quoting Kanye West’s criticism of the Bush administration’s response to Hurricane Katrina in 2005: “George Bush doesn’t care about black people.”

“It’s out of order if you question the president’s personal conduct, even if you insinuate it,” Ilona Nickels, a former congressional analyst with the Congressional Research Service and Library of Congress, told The Post. “So references to the president in that way — members who have called him a liar or a hypocrite, or accused him of being a demagogue or unethical — that language has all been challenged successfully.”

Schickler described Tuesday’s scene as yet another example of “procedural warfare” between political parties, serving as a distraction from the president’s own words to rebuke Pelosi for hers. The principle can sometimes be enforced “to the point of absurdity,” Schickler said, since it’s difficult to debate whether the president should be condemned for being racist without breaking the rule.

Democrats ran into this issue plenty of times as Trump entered the presidential race by denigrating Mexicans as “rapists” and calling for a ban on all Muslims entering the country and for mass deportations of undocumented immigrants. All the while, it remained against the rules to impugn the character of a presumptive presidential nominee or president-elect.

When a new version of Jefferson’s manual was published in 2017, it was updated to include a litany of insults that had been waged against Trump in Congress that were found to be in violation. Days after Trump was elected, Rep. Ruben Gallego (D-Ariz.) called him a “demagogue” and a “sexual predator who brags about grabbing women without their consent.”

He was told to knock off the disparaging language, to which he responded, “duly noted” — before beginning again: “Donald Trump is a bigot,” he said, only to be reminded again about his language.

It’s more common for lawmakers to be “reminded” that their language is out of order than for a lawmaker to request that their words to be taken down, as in Pelosi’s case, said Nickels. It’s even rarer for this to happen to the speaker. The last time a speaker’s words were taken down was in 1984 — and before that, not since 1797, as Nickels reported in a 1990 report for the Congressional Research Service.

On Tuesday, Hoyer pointed to two precedents, including the May 15, 1984, incident in Congress, that guided his decision to reprimand Pelosi.

The 1984 incident involved House Speaker Thomas P. “Tip” O’Neill, Democrat of Massachusetts, and Republican provocateur Newt Gingrich, then a Georgia congressman. Gingrich had recently given a speech promoting conservatism and criticizing Democrats’ approach to foreign policy while standing in front of an empty chamber while all his colleagues were away — all while C-SPAN cameras were still rolling. O’Neill called out Gingrich for the deceiving stunt on the House floor, saying, “You deliberately stood in that well before an empty House and challenged these people, and you challenged their Americanism, and it is the lowest thing that I have ever seen in my 32 years in Congress.”

Hoyer alluded to that exchange Tuesday night.

“The words of the gentlewoman from California contain an accusation of racist behavior on the part of the president,” Hoyer said of Pelosi. “As memorialized in Deschler’s precedents Chapter 29, Section 65.6, characterizing an action as racist is not in order. The chair relies on the precedent of May 15, 1984, and finds that the words should not be used in debate.”

The House speaker stood by her comments Tuesday.

“I’m proud of the attention that’s being called to it,” Pelosi told reporters, “because what the president said was completely inappropriate against our colleagues, but not just against them, against so many people in our country.”

Here’s what lawmakers are saying after President Trump told 4 congresswomen to ‘go back’ to their countries

The four Democrats — Reps. Ayanna Pressley (Mass.), Rashida Tlaib (Mich.), Alexandria Ocasio-Cortez (N.Y.) and Ilhan Omar (Minn.) — responded with a joint news conference on July 15 in which they sought to contrast their efforts on issues such as health care and immigration with the president’s actions. “This is the agenda of white nationalists,” Omar, left, said. “This is his plan to pit us against one another.” (Brendan Smialowski/AFP/Getty Images)