In a rare step, a House committee voted 22 to 14 Monday night to block a law that would make assisted suicide legal in the District, opening a new front in the conflict between congressional Republicans and the overwhelmingly Democratic capital city.

It was one of only a handful of times in the four-decade history of D.C. home rule that members of Congress have tried to use their constitutional power to overturn a city law, and the first attempt since the GOP took control of both Congress and the White House in January.

The vote was largely along party lines, as 21 Republicans and one Democrat, Rep. Jim Cooper of Tennessee, voted yes while 13 Democrats and one Republican, Darrell Issa of California, voted no.

In a split-screen moment, as the House Committee on Oversight and Government Reform was voting, more than 700 District residents and elected leaders jammed into the Atlas Performing Arts Center about a mile away for a “Hands Off D.C.” brainstorming session focused on ways to stop Congress from intervening in D.C. affairs.

“I am inspired,” said D.C. Council member Charles Allen (D-Ward 6), who organized the event and was hoarse from chanting. “What I’m hearing is that people want to act . . . We can’t just protest and pat ourselves on the back.”

D.C. Del. Eleanor Holmes Norton (D) talks with Chaffetz before a meeting in the Rayburn House Office Building on Feb. 13. (Matt McClain/The Washington Post)

Rep. Jason Chaffetz (R-Utah), the chairman of the House Oversight Committee, has pledged to intensify scrutiny of the city’s laws and policies.

Chaffetz, a Mormon, singled out the District’s law allowing doctors to prescribe fatal doses of medication to terminally ill patients as a moral issue ripe for federal intervention.

Chaffetz said his opposition to the law stems from “deep personal, moral conviction” and that it was the District, not Congress, that prompted the committee’s intrusion into local affairs. “I did not ask for this to come to me,” he said.

He said he worried that the law “will create a marketplace for death.”

“Our country should never facilitate, encourage or tacitly accept measures that prematurely end the lives of its people,” he said.

His detractors say the move is politically advantageous terrain for hard-line Republicans: assisted suicide is legal in just six states, and D.C.’s legislation has drawn national condemnation from religious groups and conservative activists.

Rep. Elijah E. Cummings of Maryland, the committee’s ranking Democrat, accused Republicans of ignoring the will of democratically elected leaders in a metropolis of 680,000. D.C. has more residents than Vermont or Wyoming but no voting representation in Congress.

(Claritza Jimenez/The Washington Post)

“None of us was elected by D.C. voters. None of us served in the D.C. city council, where the Death with Dignity Act was approved,” Cummings said. “None of the members of this committee would stand for congressional interference in their own state and local affairs, and none of us should stand for it in this case.”

Issa, the only Republican to side with Democrats, said the committee should use restraint in intervening in District affairs, adding that it did not appear that the Death with Dignity Act conflicted with federal laws. Assisted suicide is legal in Issa’s home state.

“It is not for us to make a decision as to a law that we like or dislike. It’s a question of whether or not the District of Columbia has exceeded its home rule mandate,” Issa said. “And on that, I come up short of finding so.”

Despite the committee vote, it is not clear whether Congress will be able to overturn the D.C. law. Both the full House and Senate would have to vote to block it by Friday, when a 30-day window for congressional review expires, according to D.C. officials. Some say such quick action is particularly unlikely in the Senate, where Democrats could put up a protracted fight.

But the repeal bill’s dim prospects for final approval did not mute the outrage expressed Monday by the law’s supporters, including right-to-die activists and D.C. elected officials, who rallied outside the Capitol before marching to the Atlas.

“We are tired of Congress playing politics with our laws and with our city,” council member Robert White (D-At Large) told the crowd at the rally. “Jason Chaffetz does not live in our neighborhood, his kids do not go to our schools . . . Jason Chaffetz, we did not elect you, you do not represent us; go back to Utah — it looks like you have your hands full there.”

Some say the vote to block the District’s assisted-suicide bill augurs poorly for the city’s relationship with the GOP-dominated Congress under Trump.

D.C. Mayor Muriel E. Bowser (D) called the vote “an egregious action” and said the committee had “sent a signal to D.C. residents that Congress has zero respect or concern for their will or the will of their elected officials.”

Congress reserved the authority to intervene in D.C.’s laws and budget when it passed the Home Rule Act of 1973, which allowed the city limited self-government. Federal lawmakers have periodically exercised that power, as in the 1990s, when they created a control board to pull the city from the brink of bankruptcy.

Republican elected officials have also succeeded in blocking the city from using local tax dollars to subsidize abortion services for poor women and needle exchange programs for drug users.

But incursions into city governance have stepped up over the past several years. In 2015, the House Oversight Committee voted to block a D.C. law that barred employers from discriminating against workers based on their decisions to use contraceptives, have abortions or otherwise use family-planning services.

Although the repeal effort ultimately failed, it was the first time since 1991 that the committee had voted to overturn District legislation.

Congress has also used budget riders in recent years to hamstring the D.C. government from implementing local laws.

When the District legalized marijuana, for instance, federal elected officials forbade the city to use tax dollars to regulate pot sales.

John Capozzi, a former member of the D.C. Democratic State Committee and former congressional shadow representative for the District, said Republicans in Congress have little motivation to improve their relationship with the city.

To the voters who supported Trump, D.C. local government may be synonymous with the Washington establishment the president derided on the campaign trail.

“For a lot of people, there’s not a big difference between ‘Washington’ and the D.C. government,” Capozzi said. “Going after D.C., for them, it’s like fulfilling a campaign promise. I don’t see how they have any limits.”