The Democratic National Committee (DNC) voted overwhelmingly on Saturday to limit the role of superdelegates in choosing the party's presidential nominee, moving to heal internal divisions that emerged during the bitter 2016 primaries.

The reform, adopted by voice vote at the DNC's summer meeting in Chicago, will bar superdelegates - lawmakers, former presidents and other party dignitaries - from voting during the first ballot of the nominating process.

But superdelegates would be allowed to vote in the rare instance where a second ballot was needed to nominate a presidential candidate.

The reform was pushed by DNC Chairman Tom Perez, but faced strong opposition from a relatively small but vocal group of party members, who argued it would disenfranchise some of the party's most prominent members.

Earlier on Saturday, opponents of the measure, led by former DNC Chair Don Fowler, sought to require a two-thirds majority vote to pass the reforms, arguing that doing so would require a change to the party's charter.

But committee members voted to uphold Perez's ruling that the reforms amounted to a rule change and required only a simple majority vote to pass.

Fowler then moved to suspend the rules and vote by a voice vote, paving the way for DNC members to swiftly and overwhelmingly adopt the reforms.

The reforms seek to heal divisions exposed during the 2016 Democratic nomination, when Hillary Clinton prevailed over Sen. Bernie Sanders (I-Vt.) after receiving the support of the superdelegates - "unpledged delegates" in the party's parlance.

"Today is a historic day for our party," Perez said in a statement following the vote. "We passed major reforms that will not only put our next presidential nominee in the strongest position possible, but will help us elect Democrats up and down the ballot, across the country."

Unlike pledged delegates, whose votes at the convention are determined by state primary and caucus results, Democratic superdelegates can vote for whichever candidate they prefer.

Sanders and his supporters had argued that gave party elites the power to snuff out the will of Democratic primary voters.

"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. "This has been a long and arduous process, and I want to thank Tom Perez and all of those who made it happen."

Many Democratic leaders have since come around to supporting limiting the role of superdelegates in the nomination process, including former DNC chairs Sen. Tim Kaine (D-Va.) and former Vermont Gov. Howard Dean.

House Minority Leader Nancy Pelosi (D-Calif.) has also spoken out against the role of superdelegates.

But some DNC members sought to rally opposition to the reform proposal, including Rep. Cedric Richmond (D-La.), the chairman of the Congressional Black Caucus.

Critics of the reforms argued that it would disenfranchise party leaders and create tension between Democratic lawmakers and their constituents.

Other opponents of limiting the roles of superdelegates believed it gave Sanders, a self-described democratic socialist, undue influence over the DNC.

At the end, Perez prevailed in pushing the reform, having argued it would grow trust in the party by voting members.

"Our North Star is very simple: We want to grow the party, we want to make sure that people embrace the Democratic Party and we want to make sure people trust the Democratic Party," Perez told CBS News in an interview this week.

-Updated 1:46 p.m.