Maine Democrats made clear what they think about superdelegates over the weekend at their convention in Portland: A majority of those who attended don’t much care for the party figures and elected officials who can vote as they please at this summer’s Democratic National Convention in Philadelphia.

Conventiongoers approved a rule change Saturday that will require future superdelegates from Maine, in 2020 and thereafter, split their votes for the party nominee proportionally, based on how Democrats vote in their nominating contest.

Vermont Sen. Bernie Sanders, who won Maine’s caucuses with 64 percent of the vote, praised the move.

“Maine is trying to make the Democratic Party more democratic,” he said in a statement released by his campaign. “I hope other states follow Maine’s example. This is the kind of grassroots democracy that will help the Democratic Party grow and win elections.”

Maybe. But before more state Democratic parties follow suit, it’s worth considering why superdelegates exist.

The American political system operates on the unwritten principle that two competitive parties largely dominate it. As long as that principle stands, it’s as much the Democratic Party’s responsibility to reflect the will of its members and Democratic primary voters as it is to remain a competitive player in national politics.

To that end, the Democratic Party sets rules aimed at ensuring it remains as competitive as possible in national elections, and superdelegates are part of that difficult balance of responsibility to the party’s base and the party’s obligation to be competitive among the electorate at large.

Superdelegates date back to the 1984 nominating contest, which followed a string of decisive presidential defeats for Democrats. There was the 1968 election, in which Democrats nominated Hubert Humphrey, even though the Minnesota senator didn’t participate in a single primary contest and didn’t earn the support of Democratic voters. Humphrey went on to lose to Republican Richard Nixon. Four years later, when the Democratic nomination was fully decided by primary votes, Democrats nominated George McGovern, who lost in a landslide to Nixon.

Since 1984, superdelegates have represented about 15 percent of the vote at the Democratic National Convention. They’re intended to act as a kind of moderating force that ensures Democrats choose candidates more palatable to voters in a general election.

But they’re not necessarily the antithesis of a democratic nominating process.

They’ve never gone against the will of the majority of Democratic primary voters. Even this year, while Sanders and his supporters highlight the reality that Hillary Clinton will likely command the support of superdelegates in a number of states (such as Maine) in which Sanders won the popular primary or caucus vote, Clinton is on track to win more pledged delegates — the class of delegates representative of the popular vote — than Sanders. Plus, the overwhelming majority of Democratic superdelegates are Democratic National Committee members who have been elected by party delegates in each state.

It’s also worth noting that the Democrats’ “pledged” delegates aren’t technically bound to support a particular candidate, so they are also free to go against their states’ popular vote.

While Democratic superdelegates have never — as a group — defied the will of primary voters, they offer their party additional flexibility to respond to political realities. Since they can change their preference at will, they can guard against the possibility of the party nominating a candidate who amasses significant support in early primaries but faces a career-ending scandal just as primary season is winding down. (Imagine if former North Carolina Sen. John Edwards were a stronger contender in 2008, before revelations of his affair and child with a campaign aide as his wife was dying of cancer derailed his candidacy. That’s a hypothetical circumstance cited by the Brookings Institution’s Elaine Kamarck.)

Superdelegates to this year’s Democratic National Convention face a choice: Do they decide to back the will of the majority of Democratic voters in their state, or do they cast a vote more out of concern for their party’s electoral chances in November?

The superdelegate system is designed with some of those considerations in mind. To date, they haven’t cast the decisive votes in the Democratic Party’s nominating contest. And they likely won’t this year.

But perhaps, in some future election, the party will be happy that it has superdelegates with flexibility to react.