Well past midnight on the first day of President Trump’s Senate impeachment trial this week, after nearly 12 hours of increasingly acerbic comments by the House managers prosecuting the case and the White House lawyers defending the president, Chief Justice John G. Roberts Jr. interjected. In his typically calm tone, the presiding Roberts reminded both sides that they were “addressing the world’s greatest deliberative body.” He said the Senate had “earned that title because its members avoid speaking in a manner and using language that is not conducive to civil discourse.” He even offered a charming anecdote about a 1905 Senate impeachment trial in which one of the managers dared to use the word “pettifogging” in that hallowed chamber. “I don’t think we need to aspire to that high of a standard,” Roberts said, musing over the objection to a term that meant overemphasizing petty details, “but I do think those addressing the Senate should remember where they are.”

On its face, the admonishment sounded like a good and healthy thing, an encouragement for respect, a reminder of Senate history — not only a call for civil discourse, but a gently delivered act of civility itself. Roberts’s words, however, failed to take into account the backdrop: a deeply partisan and increasingly authoritarian political dynamic that has catapulted the country into a moment of crisis. In this context, the smooth veneer of civility, rather than being uplifting, might actually facilitate the downward spiral. In this context, civility is dangerous, a weapon that serves both as a shield, covering up malign acts, and a sword, parried at the opponent who dares to be “uncivil” and so shifting the focus away from the true danger.

Roberts’s interjection — his only one in the proceedings so far — harked back to a Senate that may have held more courteous trials and sought to minimize the harshest cut and thrust of partisan debate. But consider what caused the chief justice to speak. Rep. Jerrold Nadler (D-N.Y.), possibly the bluntest of the House managers, had said this, after a long day and night of votes delaying, and possibly scuttling, consideration of whether witnesses and documents should be part of the trial: “So far I’m sad to say I see a lot of senators voting for a coverup, voting to deny witnesses, an absolutely indefensible vote, obviously a treacherous vote.” When White House Counsel Pat Cipollone, who is leading Trump’s defense team, took the floor, he responded: “The only one who should be embarrassed, Mr. Nadler, is you, for the way you’ve addressed this body. This is the United States Senate. You’re not in charge here.” Enter the habitually ambivalent Sen. Susan Collins (R-Maine), one of the handful of Republicans whose votes are considered essential if the trial is to have witnesses. She passed a note to the chief justice, later telling reporters she had been “stunned” and felt compelled to ask Roberts to intercede.

But the outrage rang hollow for those who have watched Republicans stand idly by when Trump engages in ad hominem attacks against Democrats and fellow Americans and degrades the institutions and values that have sustained the democracy. “Crazy Bernie,” “Sleepy Joe” and Mini Mike,” he calls three of his opponents in the 2020 presidential campaign. “Shifty Schiff,” he calls Rep. Adam B. Schiff (D-Calif.), who is leading the impeachment prosecution. “Human scum,” he calls his “Never Trumper” Republican critics. His response in the aftermath of the civility sideshow was more of the same. From the world stage in Davos, Switzerland, Trump said of Nadler and Schiff: “These two guys — these are major sleazebags. They’re very dishonest people. Very, very dishonest people.” Had Trump been present at his own trial, would Roberts have dared to remind him to be civil?

Of course, the answer is not to toss aside decorum or the basic process of governance, one in which elected officials treat each other with courtesy and decency as they hammer out their differences over issues of the day. There is a real danger that when each side further inflames the other, matters may slip out of control. Finding points of mutual understanding can seem increasingly impossible, accelerating the toxic division and making the very notion of moderation lose all relevance. But when civility means treating both sides as equal, when a mind-bending onslaught of lies (The Washington Post counts over 16,000 “false or misleading claims” by Trump in his first three years in office) is expected to be met with courtesy, a demand for civility risks becoming an instrument of power by the majority party to neutralize or even silence criticism and the critics.

Roberts chose not to interject into the Senate trial when House managers pleaded for the most basic tools of a fair trial — witnesses and documents. Nor did he offer a response when Cipollone falsely claimed Republicans were denied access to the sensitive compartmented information facility, or SCIF, during the House inquiry. About these matters the chief justice was silent. His only interruption, however heartfelt, gave the appearance that the leader of the nation’s highest court was more interested in maintaining the status quo than serving justice and truth.

An emphasis on civility plays another role, historically. The history of racism and civil rights, for example, shows that the tension created by an expectation of civility served to suppress black voices and keep a lid on the possibility of violence. The current demand for civility, while not only about this, also reflects a fear of violence: Lurking under the surface and occasionally bubbling up online and on cable TV is the threat of civil war if Democratic opponents go too far; this often includes a reminder of how well-armed Trump devotees are (and might explain why many Americans are reluctant to take to the streets in protest, as they were at a gun-rights rally in Richmond last week). Civility deployed this way is not about improving the quality of our body politic and public discourse, but aimed at keeping critics quiet.

It is worth noting that Trump, throughout his career, has exploited the civil process of U.S. courts and the general civility of those who refuse to assume the worst. The societal expectation of civility (and the disbelief toward the utter lack of it) has made it easier for him to get away with so much — tearing apart migrant families and losing track of the children’s whereabouts, for example, or covering for Saudi Arabia Crown Prince Mohammad Bin Salman and the Saudis after the murder of journalist Jamal Khashoggi.

There is no question the use of uncivil language by politicians, commentators and journalists has escalated. I count myself among those who have felt reluctantly obliged to choose increasingly vivid words to accurately capture and respond to a growing picture of criminality and corruption and an increasing awareness that the president of the United States acts with a level of anti-democratic malignancy and cruelty I fear puts our institutions, global alliances and vulnerable populations in increasing danger.

But if you believe your house is on fire and your family faces death and destruction, is it appropriate to engage in pleasant and polite tones when speaking to the alleged arsonist and his accomplices? Is that not the time to speak and act with clarity to spur action and put out the fire? (Activist Greta Thunberg has argued similarly in response to the climate crisis: “Now is not the time for speaking politely.”) Political wisdom aside, was Nadler’s assertion on the Senate floor early Wednesday morning so far out of bounds?

In October, during Game 5 of the World Series, commentators debated about the appropriateness of booing and, particularly, chants of “Lock him up” when Trump visited the Nationals’ stadium. That booing was disrespectful to the office of the presidency, some said. As for the chanting: “We are Americans, and we don’t do that,” insisted MSNBC host Joe Scarborough. For average citizens in attendance, however, this was an opportunity to communicate their opinion directly to the president. It is a sign of the lingering strength of our democracy that such dissent remains possible. What would it say if sports fans were afraid to express themselves, especially in the raucous environment of a major league baseball game?

Even though the Senate floor is not a sporting arena and may be one of the final public refuges for “appropriate” behavior, the civil-minded Roberts walks a precarious line in these deeply rancorous times. In 2014, years before the current apex, he worried that the Supreme Court was at risk of being perceived as merely partisan. “I don’t want it to spill over and affect us,” he said at the University of Nebraska. “That’s not the way we do business. We’re not Republicans or Democrats.”

Yet as much as Roberts may want to be above politics and advocate for the value of civil discourse for the good of the courts, the Senate and the nation — perfectly noble and necessary goals — his position of civil neutrality in this Senate proceeding may ensure his reluctant role in this troubled chapter of the nation’s history only hastens the unraveling. Is truth not a defense against incivility?