The Democratic National Committee voted Saturday to curb the power of so-called “superdelegates,” limiting how influential major members of the Democratic Party — and major donors — are in selecting the party’s presidential candidate.

Superdelegates make up around 15% of all voting DNC delegates and “include governors, members of Congress, mayors and others.”

Fox News reports that the reforms, which were authored earlier this year, force the superdelegates to wait until the second ballot at the Democratic National Convention before weighing in on which presidential candidate they prefer. This, the more progressive wing of the DNC claims, will help limit superdelegate influence, both on the process and in selecting the final candidate.

Supporters of former presidential candidate Bernie Sanders have been pushing superdelegate reforms on the theory that Sanders would have secured the presidential nomination in 2016 had it not been for the 15% of delegates who operate outside the primary and caucus system — all of whom were firmly in Hillary Clinton’s camp.

Sanders’ complaints are speculative, but DNC emails, revealed through a hack late in the presidential campaign cycle in 2016, show the foundations of a concerted effort to direct the nomination to Hillary Clinton, despite Sanders’ early successes in states like Iowa.

There’s no guarantee the reforms will mean much of a change in how the Democrats’ candidate is chosen. The superdelegates could choose to exercise their influence earlier in the process, or Sanders’ influence over party politics could turn out to be outsized (a likely scenario), and progressive candidates will still fail at the presidential level.