After a two-year battle to reform the Democratic party’s presidential nominating process—and assuage the disparate wings that have contentiously debated its future since 2016—the Democratic National Committee voted on Saturday afternoon to reduce the role of superdelegates as part of a broader historic reform package.

The committee’s members voted in Chicago at the DNC’s annual summer meeting to strip the ability of superdelegates to vote on the first ballot at the presidential nominating convention. These superdelegates, which include members of Congress and DNC members, will still have the ability to pick any candidate of their choosing no matter how the public votes in primaries and caucuses. But they will now only be allowed to substantively vote at the convention in a case where the race is contested—meaning that after a number of rounds of votes, no single candidate emerges as the overall victor—or once the outcome is not in doubt.

The subject of superdelegates had been an acrimonious one since the 2016 Democratic primary, during which supporters of Sen. Bernie Sanders (I-VT) deemed them part of a “rigged” process, as the majority of powerful members in the party favored Democratic nominee Hillary Clinton. Though superdelegates did not overturn the will of the voters, who selected Clinton, the reform measure was meant to serve as a bridge between the supporters of each candidate and a means of preventing a sense that one candidate was overwhelmingly favored in the future.

“These reforms will help grow our party, unite Democrats, and restore voters’ trust by making our 2020 nominating process the most inclusive and transparent in our history,” DNC chairman Tom Perez said in a statement. “Most importantly, these reforms will empower voters and ensure that they feel like their voices are being heard, especially young people who share the Democratic Party’s values.”

The issue of reform actually united Sanders and his supporters with Perez, who was not their favored pick as the head of the DNC and remains a subject of criticism at times.

“Today's decision by the DNC is an important step forward in making the Democratic Party more open, democratic and responsive to the input of ordinary Americans,” Sanders said in a statement after the vote. “This has been a long and arduous process, and I want to thank Tom Perez and all of those who made it happen.”

The reforms also target how caucuses and primaries function, including requiring caucuses to have absentee voting and encouraging the state parties to institute same-day or automatic registration for the primaries.

All of this had been debated prior to the 2016 convention and shepherded by the Unity Reform Commission, which spent eight months coming up with the initial proposal. That was followed by over 80 hours of conversations by the Rules and Bylaws Committee to finalize what would be voted on, before the full vote of members at this weekend’s meeting.

The conclusion was not without last-minute drama, as some opposed to the reforms made their voices heard over the weekend, arguing that because of the number of African-American members that are superdelegates, stripping their power would essentially keep them from having influence over the process.