PHILADELPHIA — Democrats are about to have a delegate fight of their own. Following the Republican’ controversy over bound and unbound delegates, the Democratic National Convention is about to go headlong into a conflict over superdelegates in its rules committee this weekend.

The DNC’s rules committee is expected to convene Saturday morning, where groups are planning to gather outside the city’s convention center and urge the party to end the superdelegate system.

According to a media advisory, the pre-vote press conference with rules committee members includes a formal petition delivery of more than 500,000 signatures collected by Democratic-leaning groups working to end the use of superdelegates at the Democratic National Convention.

A superdelegate is a party official or elected official who is free to cast a vote for any candidate for the presidential nomination at the party’s national convention, regardless of whom the voters of their state prefer. This is in contrast to a “pledged delegate” who must cast their ballot in accordance to the winner of their state party’s primary.

DNC rules committee members are expected at the press conference and include Aaron Regunberg, the amendment’s chief sponsor. Groups presenting the signatures will include: MoveOn.org, Demand Progress, Daily Kos, Social Security Works, Democracy for America, New Democrat Network, National Nurses United, The Other 98%, Courage Campaign, Progressive Kick, Credo, PCCC, Progressive Democrats of America, Center for Popular Democracy, Social Security Works, and Reform the DNC.

“This is a historic moment for the Democratic Party,” said Aaron Regunberg, Rhode Island state representative and rules committee member. “Saturday we vote on whether to end the undemocratic superdelegate system. It’s time to restore democracy in the Democratic Party.”

Supporters of former Democratic presidential candidate Bernie Sanders became frustrated with the superdelegate system, as they saw it as a way that damaged the Vermont senator’s candidacy during the party’s primary against former secretary of state Hillary Clinton.

“The super delegate system undermines the promise of one person one vote that is bedrock of democracy,” added Deborah Burger, RN, co-president of National Nurses United and rules committee member. “It was created to block the nomination of candidates who would challenge a political system that has for far too long been dominated by corporate interests and a wealthy elite. Ending this undemocratic selection process would be a strong step forward to making the Democratic Party more responsive to those thirsting for real change and a healthier America.”

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