Sen. Joe Manchin (D-West Virginia) says he will likely vote with Republicans to block a D.C. bill that overhauls the city’s criminal code, significantly raising the prospect that Congress could overturn a local city measure for the first time in three decades.

Manchin told CNN on Monday that even though he hasn’t fully read up on the sweeping 450-page bill passed by the D.C. Council late last year, he opposes provisions that lower maximum penalties for certain offenses. “I don’t support it. I mean, I want to put people away, I don’t want to let them out,” he said. “I haven’t been briefed on it, but what I know about it, I would vote to rescind it.”

Manchin’s office confirmed his statements to DCist/WAMU.

The West Virginia senator’s announcement could seal the fate of the controversial bill, largely because Democrats only hold a two-vote majority in the chamber and the resolution to block the bill requires a simple majority to pass. Sen. John Fetterman (D-Pennsylvania) remains hospitalized for clinical depression, meaning that the full roster of Republicans plus Manchin would give the resolution enough votes to pass.

Earlier this month the Republican-led House passed its own disapproval resolution on the bill. Critics of the D.C. bill — which revises and modernizes the city’s century-old criminal code — say it’s soft on crime, largely because it decreases maximum prison sentences for certain offenses. The bill also does away with mandatory minimum sentences for everything but first-degree murder, expands the right to a jury trial to people charged with misdemeanors, and gives convicted felons who have served 20 years of their sentence the opportunity to ask a judge for early release.

But proponents of the overhaul — which was more than a decade in the making — say it updates criminal offenses to make it easier to prosecute offenders, and only lowers specific penalties to match the sentences judges were actually handing down. They also note that the changes don’t take effect until late 2025, and will thus make no difference with respect to the current spike in certain violent crimes in D.C.

More broadly, though, D.C. officials argue the revision of the criminal code is a local matter that should be left to local officials. While Congress has the legal right to interfere in local affairs, including by blocking bills passed by the council, last week the city’s leaders urged senators not to do so.

“The insult of limited home rule is that the 700,000 D.C. residents and taxpaying Americans, and their duly elected officials, must endure the review and oversight of our laws by officials not elected to represent our interests or values,” wrote Mayor Muriel Bowser, who in January vetoed the overhaul of the criminal code, but later proposed changes to it.

“Ironically, many who have expressed support for overriding these two D.C. local laws have long espoused the virtues of freedom from federal government interference and respect for states’ rights. They have argued that myriad matters, including criminal justice, reproductive freedom, and voting rights, are best left to states and localities. The current calls to formally disapprove District law contradict those principles and would substitute the will of federal politicians for the decisions of locally elected leaders,” wrote D.C. Attorney General Brian Schwalb in his own letter to Democratic leaders in the Senate.

“It is highly problematic for the District if Congress steps in to interfere with home rule,” wrote the 13 members of the council in their own missive to senators. “We could, of course, better explain this — and the legislation — if there were a hearing where we were invited to do so.”

The bill’s prospects in the Senate seemed shaky as soon as the House voted on its own disapproval resolution, which included the support of 31 of the chamber’s Democrats. Republicans have pushed on crime and public safety as political issues that could imperil vulnerable Democrats, and Manchin’s announcement that he’s likely to vote for the bill isn’t an unexpected break for the conservative Democrat. In 2021, Manchin said he opposed a bill to make D.C. the 51st state.

“It’s a raw nerve with a lot of the American people. They look at the cities today and they say they’re not safe places. I think it’s a problem for Democrats to oppose something that would make some of our larger population centers more safe,” Senate Republican Whip John Thune of South Dakota told CNN. “My expectation is that some Democrats here in the Senate would vote for it. Then it would be up to Biden about what he wants to do.”

While the White House has said that Biden opposes congressional efforts to block D.C. bills, it did not specifically say he would veto any such disapproval resolution that gets sent to his desk. The last time Congress passed a disapproval resolution and the president signed it was some three decades ago; since then, disapproval resolutions have died somewhere in the process. (For most D.C. bills, Congress has a 30-day window to block them, but for any bills dealing with criminal offenses the review period extends to 60 days.)

The Senate is expected to take up the disapproval resolution on the overhaul of D.C.’s criminal code by next week.