The Democratic National Committee’s two-year debate over its presidential primary rules came closer to resolution Wednesday, as its key rulemaking body voted to curtail the power of unpledged delegates — so-called “superdelegates” — at the next convention.

At the end of a three-hour conference call, which was opened to the public, the Rules and Bylaws Committee adopted a compromise that grew out of lengthy negotiations between supporters of Hillary Clinton’s 2016 campaign and supporters of Sen. Bernie Sanders (I-Vt.).

In the past, superdelegates were able to vote on the first ballot at the convention, for any nominee. The new rule would prohibit superdelegates from voting until a second ballot, or in the event a candidate arrived at the convention with enough pledged delegates — earned in primaries and caucuses — to secure the nomination.

“It fulfills our mandate without disenfranchising the people who have built the Democratic Party,” DNC chairman Tom Perez said near the start of the call. The reform, he said, would “rebuild the trust among many who feel, frankly, alienated from our party.”

Within an hour of the call’s conclusion, Sanders said the negotiations had done the trick.

“This decision will ensure that delegates elected by voters in primaries and caucuses will have the primary role in selecting the Democratic Party’s nominee at the 2020 convention,” Sanders said in a statement. “This is a major step forward in making the Democratic Party more open and transparent, and I applaud their action.”

On the call itself, dissent was largely limited to one rules committee member: former DNC chairman Don Fowler. In a series of back-and-forths, Fowler argued the reform would devalue the party activists and elected officials who made up the superdelegate pool.

“I oppose plans that change the system that we know works,” he said. “We have followed an illogical process to argue for superdelegate reform.”

Fowler was outvoted by every member of the committee, in a discussion that briefly paused when former DNC chair Donna Brazile shared the news that Supreme Court Justice Anthony M. Kennedy would be retiring this year.

“Oh my god!” shouted one member on the call.

“This is not good,” Brazile said.

“Not that he’s been any good for us on these recent decisions,” said the rules chairman, Jim Roosevelt.