WASHINGTON — After a heady few years for the District of Columbia’s longtime aspirations of self-governance, with a statehood bill even passing in the U.S. House of Representatives in 2021, the temperature between Congress and the city it sits in has plummeted to new lows.

On Thursday, the House voted by large margins for two disapproval resolutions that would overturn a pair of laws passed by the Council of the District of Columbia, invoking its rarely used powers to weigh in on D.C. legislation. The measures now go to the Senate.

It was the latest congressional salvo against the city’s government since Republicans took control of the House last month for the first time since 2019. Some have been minor: Under the House’s new rules package, the mayor of D.C. was stripped of her privileges to access the House floor. But some have verged on the existential: In the boldest broadside against the city in years, some Republicans have called for an outright repeal of the 50-year-old Home Rule Act, which allows the 713,000 residents of the District to elect a mayor and council.

“I think there’s some very rocky times ahead,” said Irvin B. Nathan, a former attorney general for D.C. and, before that, general counsel of the House. “What they’re threatening is much more serious than what we’ve had in the last couple of decades.”

At this early point in the new congressional session, much of the antagonism is symbolic, and D.C. officials nervously hope it stays that way given that Democrats hold the Senate and White House. It has been more than three decades since Congress successfully overruled a local law through a disapproval resolution, voting in 1991 to annul a measure that would have allowed the construction of an apartment and office complex 20 feet above the city’s downtown height limit.

Still, dozens of House Democrats voted with the Republicans on Thursday, making proponents of the local legislation at issue more uneasy than they had been before the vote.

Though members of Congress have tried and failed to overrule D.C. laws a number of times since the early 1990s, they have been quite successful at interfering by other means. Through the use of amendments on big funding bills, Congress has banned the city’s ability to tax and regulate the sale of cannabis, and prohibited the spending of city funds on abortion services for Medicaid recipients. In past years, the city has been barred from using its own funds for a needle exchange or allowing city workers’ health insurance plans to cover their domestic partners.

Supporters of D.C. autonomy insist that such moves indicate a belief on the part of some lawmakers that, as Representative Eleanor Holmes Norton, the District’s nonvoting House delegate, said on Thursday, “D.C. residents, a majority of whom are Black and brown, are either unworthy or incapable of governing themselves.”

The two laws that were disapproved on Thursday — one allowing noncitizens to vote in local elections, and endorsing an ambitious rewrite of the District’s century-old criminal code — were perfect partisan targets, prompting speeches on the perfidy of allowing “illegal aliens” to cast ballots and on the urban chaos unleashed by “soft-on-crime” policies.

But House Republicans maintained that they were concerned for “our neighbors who are traumatized, injured, that have to live in fear,” and that Congress had the clear authority under the Constitution to review and potentially block all legislation in the District.

“We’re exercising our constitutional right to say no to this madness,” Representative Steve Scalise of Louisiana, the Republican majority leader, said during Thursday’s debate.

As he and other Republicans pointed out in their floor speeches, the politics around the criminal code overhaul are particularly complicated.

The rewrite, which runs hundreds of pages, is the product of more than a decade of work, most of it by a commission working with input from prosecutors, public defenders, academics and city officials. Members of the commission describe it as driven by research and deliberation rather than ideology: adjusting the range of penalties to account for the way they are levied in practice; including basic modern elements of criminal law, like codifying the requirements for a self-defense claim, that have been missing from the code; and adding gradations to existing offenses so that charges can better fit alleged crimes.

The vast majority of these updates are uncontroversial. But in a city enduring a multiyear rise in murders and carjackings, certain elements of the rewrite drew quick pushback. The new code lowers maximum sentences for some crimes, including robbery, carjacking and illegal possession of a firearm, and allows defendants to request a jury trial for misdemeanor charges that could lead to prison time, a right that was curtailed by the D.C. Council in the early 1990s because of an overcrowded court system.

The city’s mayor, Muriel E. Bowser — along with police unions, editorial writers and the local U.S. attorney’s office — expressed reservations about some of these changes, citing current crime trends. As in cities across the country, the number of homicides in D.C. rose steeply during the pandemic years, and the number of carjackings has continued to climb precipitously. At the same time, the court system has been backlogged in part because of judicial vacancies, a problem that, in the District, can be fixed only by Congress.

Proponents of the revised criminal code argue that all of the changes simply bring it in line with the codes of other states. Most states allow jury trials for misdemeanors, and the new sentencing maximums, they argue, are well within the standard range. The new maximum for carjacking, for example, is longer than the statutory maximum in Georgia, the home state of Representative Andrew Clyde, the Republican who sponsored the disapproval resolution.

Still, Ms. Bowser vetoed it on Jan. 4, while emphasizing that “approximately 95 percent” of the code rewrite had “consensus agreement.” Two weeks later, the council overrode her veto. Then Congress stepped in.

While the House’s disapproval resolutions were expected, there is less certainty about what may come. Some wonder if the mayor’s public reservations about the new criminal code, even though she has emphasized that she does not want Congress to intervene, would give cover to enough Democrats in the Senate to vote for disapproval. Even if the resolutions fail, Congress could add budget amendments barring the city from spending funds to put elements of the new laws into practice.

What does seem clear is that the renewed conflict between the District and its most prominent local work force is just beginning.

“For as long as I’ve been in Congress, and I’ve been in Congress for 30 years and then some,” Ms. Holmes Norton said, “this is a new level of hostility to the District of Columbia.”