Sen. Joe Manchin III (D-West Virginia) said Friday that he opposes the current bill to make D.C. the 51st state, adding that he’d prefer to see the issue taken up through a constitutional amendment.

“If Congress wants to make D.C. a state, it should propose a constitutional amendment. It should propose a constitutional amendment, and let the people of America vote,” he said in an interview with a West Virginia radio station.

Manchin’s position throws a bucket of cold water on the D.C. statehood movement, which has been riding high since President Biden endorsed the cause and the House of Representatives passed a statehood bill last week for the second time in as many years. But Manchin isn’t the only obstacle the bill faces in the Senate — even if every Democrat endorses the measure, which hasn’t yet happened, it would take eliminating the filibuster to get it past Republicans who have remained dead set against creating a new (and likely Democratic) state.

In the interview, Manchin said his position stemmed from constitutional concerns over the 23rd amendment, which was passed in 1961 and granted D.C. three electoral votes.

Republicans and conservative groups have long made the same argument, saying that the amendment’s passage and language indicates that D.C. statehood can only be achieved by amending the Constitution, not through simple congressional legislation. Republicans also say making D.C. a state without repealing the 23rd amendment would result in a situation where those left in the federal district — essentially, just the occupants of the White House — would theoretically have three electoral votes of their own.

Democrats and statehood advocates say the argument over the 23rd amendment is a distraction, and that Congress could quickly move to repeal it. They also argue that admitting new states to the union has been done in the past by simple congressional legislation. (That includes West Virginia.)

D.C. Congresswoman Eleanor Holmes Norton dismissed Manchin’s concerns on those grounds in a press release.

“I was not surprised by Senator Manchin’s comments. He is a Democrat from a very Republican state,” she told DCist/WAMU. “But I don’t find his comments particularly compelling.”

But Manchin said that Congress had the chance to consider D.C. statehood before it passed the 23rd amendment, and it balked. “They could have chose statehood back then, retrocession to Maryland … or we can grant electoral votes. They chose to grant three electoral votes,” he said.

Any constitutional amendment to give D.C. statehood would require both congressional legislation and ratification by 38 states, a high bar given Republicans’ overall opposition to statehood for the city.

A constitutional amendment to change D.C.’s status has been tried in the past — and it failed. The District of Columbia Voting Rights Amendment that Congress approved in 1978 would have repealed the 23rd amendment, given the city full congressional representation — the same number of electoral votes as the smallest state — and the ability to participate in any future attempts to amend the Constitution. The amendment was only ratified by 16 states in the seven-year time period allotted for constitutional amendments.

Republicans have recently floated an alternative to D.C. statehood — that the city be retroceded to Maryland. But neither D.C. nor Maryland officials have expressed any support for the idea, and some statehood supporters have said retrocession is a distraction and poses its own legal and logistical challenges.

Manchin — who has become something of a kingmaker in the evenly divided Senate — also said that the current D.C. statehood bill would likely face lawsuits, and advised that a constitutional amendment would be the safer alternative.

“You know it’s going to go to the Supreme Court,” he said. “So why not do it the right way and let the people vote, to see if they want to change?”

Norton said she hadn’t been counting on Manchin’s support in the Senate, and indicated that she hadn’t spoke to Manchin before or after his public comments. Instead, Norton said she hopes the popularity of President Joe Biden’s coronavirus relief package and other agenda items will propel Democrats to add seats in the midterm elections next year, which would make Manchin’s vote less consequential.

She is also anticipating a robust hearing for the statehood bill in the Senate, which she said she sees as another venue to explain the arguments for statehood to Americans across the country.

“I think the next step are hearings in the Senate, which we expect to bump up support in the country and in the Senate once this issue is laid out,” she said. “It’ll be the first time that there has been a Senate hearing.”

This story has been updated with comments from D.C. Delegate Eleanor Holmes Norton.