The Democratic National Committee passed new rules Saturday that will sideline superdelegates in the presidential selection process — a radical shift that was pushed by the party’s left-leaning Bernie Sanders wing.

The change will sharply reduce the power of party insiders in the 2020 primaries. Coming ahead of November’s crucial midterms, the move also signals the Democrats’ increasing reliance on young progressive voters who they hope will turn out in unprecedented numbers this fall.

“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.

Under the party’s previous rules, about 15 percent of those who chose the Democratic presidential candidate at its national convention were superdelegates, free to support anyone they wished to be their standard-bearer.

All other delegates were pledged to a particular candidate, based on the results of state primaries and caucuses.

Party bigwigs — from governors and state legislators to former presidents and donors — have usually served as superdelegates. In the past, the party often relied on their influence to temper the passions of the left-leaning Democratic base.

In 2016, Hillary Clinton used that history to her advantage. As the party establishment’s favorite, she locked up the support of a majority of the superdelegates before a single primary ballot was cast — effectively barring the door for her insurgent opponent, Vermont Sen. Bernie Sanders.

In Wisconsin, for example, Sanders walloped Clinton by 14 percent, winning 57 percent of the primary vote. He gained 49 delegates with his victory — but Clinton picked up 47, thanks to her edge with the state’s superdelegates.

Ever since, the party’s progressive wing has agitated for Saturday’s change.

Under the new rules, superdelegates will still be named. But they will only be allowed to vote if the convention deadlocks and fails to settle on a presidential candidate on its first ballot.

Committee members adopted the measure on a raucous voice vote in a Chicago hotel ballroom where they are holding their annual meeting.

Opponents of the change warned that it risks alienating moderate Democrats.

“What I witnessed was a political murder-suicide,” Bob Mulholland, a superdelegate from California, told Politico.