Bernie Sanders is far behind Hillary Clinton in the delegate count toward the Democratic presidential nomination, but part of his strategy is to hold out hope that superdelegates will back him at the convention.

What are superdelegates? They’re roughly 700 party officials and other high-profile Democrats who get to vote on nominees at the convention. In theory, they could swing a tight race to one candidate or another.

The vast majority of superdelegates have said they will back Clinton, according to news reports. But Sanders has suggested that in states where he won by double-digit margins, superdelegates should vote according to the wishes of people in their states.

That led to Fox Business News ’ Maria Bartiromo asking Democratic National Committee chairwoman Debbie Wasserman Schultz for her take on superdelegates.

Wasserman Schultz countered that superdelegates aren’t so powerful, according to history.

"The purpose of superdelegates -- which by the way, have never been a determining factor in who our nominee is since they've been in place since 1984 -- is to make sure that party activists who want to be delegates to the convention don’t have to run against much better-known and well-established people at the district level," said the South Florida congresswoman.

Have superdelegates not mattered since they were introduced in 1984? It’s clear that in elections after 1984 they were never needed to settle a nomination. However, they did play a role in 1984, although experts are conflicted about the extent of their power.

Superdelegates started in 1984

Under the Democratic Party’s system, slightly more than 700 party officials and big shots get a vote as a superdelegate. That’s about one-third of the 2,383 delegates needed to secure the nomination, or about 15 percent of the total delegates. While pledged delegates vote for the candidate they were elected on behalf of, the superdelegates can vote for whomever they want at the convention.

The superdelegate system was added in the 1980s after the Democratic party suffered huge losses with George McGovern in 1972 and Jimmy Carter’s failed re-election bid in 1980. The party wanted to come up with new ideas, with hopes of primaries resulting in candidates who were more likely to win general elections. A commission was formed and proposed a few reforms, including the superdelegates.

The best example of when superdelegates played a role was the first year they started: former Vice President Walter Mondale’s nomination in 1984. (Ironically, the superdelegate system didn’t guarantee the results the party hoped for, because Mondale got crushed by Ronald Reagan in the general election.)

Experts disagree how much credit superdelegates should get toward Mondale winning the nomination. Here is a quick snapshot:

Entering the final handful primaries on June 5, 1984, Mondale was leading Sen. Gary Hart in the delegate count, with Jesse Jackson far behind. The battle for delegates became more dramatic that night when Hart won three primaries -- including the big prize of California in a cliffhanger.

The Mondale campaign said -- and some news reports agreed -- that Mondale secured the needed 1,967 delegates that night in spite of losing California. But the Associated Press concluded he was "barely short of the magic majority."

Mondale wanted to make it indisputable that he had enough votes -- and his campaign set a deadline of one minute before noon. So he made 50 calls in three hours to nail down an additional 40 superdelegates and declared at a press conference that he had 2,008 votes.

At the convention in July, Mondale won on the first ballot.

Sean Bartlett, a spokesman for the DNC, argued that Mondale won the nomination with pledged delegates, although he said that "superdelegates came close to being decisive."

Bartlett pointed to a February 2016 article in The New Republi c which stated that while superdelegates preferred Mondale , he "ultimately won a plurality of delegates. So while superdelegates put him over the top, he was also the narrow choice of the voters."

Priscilla Southwell -- a professor at the University of Oregon who wrote an article about the 1984 Democratic nomination -- told PolitiFact Florida that she disagreed with Wasserman Schultz’s conclusion that superdelegates have never been a determining factor.

"I agree that Mondale had a plurality of pledged delegates, but he did not have enough delegates to clinch the nomination on the first round without the superdelegates. So, if the superdelegates had not been there in 1984, there would have had to be a second roll call of the states, and who knows who would emerged as the nominee?"

But Elaine C. Kamarck, who was in charge of counting delegates for Mondale, told PolitiFact Florida that Mondale could have won on pledged delegates alone.

"It wasn’t that there weren’t enough -- the California primary came up short for him, so he didn’t get the magic number. There were plenty of delegates without the superdelegates to go over the top," she said. "I’d say they were very helpful in helping him get the nomination, but he would have gotten the nomination even without that burst in the end, because there were enough random uncommitted delegates that he could have done it."

(Uncommitted delegates are similar to superdelegates in that they can make up their mind at the convention. But superdelegates hold that position by virtue of their office -- for example, the president is one.)

Kamarck, who worked in Bill Clinton’s White House, is a superdelegate who plans to vote for Hillary Clinton and is a lecturer at Harvard .

In subsequent elections, a Democratic candidate had enough delegates early on so that the superdelegates were essentially irrelevant.

In 2008 , Clinton led Barack Obama in the superdelegate count in January but he overtook her by May. She suspended her campaign in June a couple months before the convention.

Super delegates in 2016

So could superdelegates make a difference this year? It’s too soon to say for certain, but it appears unlikely.

The blog fivethirtyeight determined in February that "superdelegates are mathematically relevant when a candidate has 41.2 percent to 58.8 percent of elected delegates."

As of March 22, if we count pledged delegates Clinton has about 48 percent of the needed 2,383 delegates to win, while Sanders has 35 percent.

Julia Azari, professor of political science at Marquette University, told NPR that superdelegates would only make a difference if it’s close.

"I think the only chance a superdelegate will make a difference is if there isn’t really an obvious preference coming out of the electorate part of the process."

Our ruling

Wasserman Schultz says superdelegates "have never been a determining factor in who our nominee is since they've been in place since 1984."

The first election where Democrats used superdelegates was in 1984, where they helped Mondale secure the nomination on the first ballot at the convention. It’s not clear that they were the "determining" factor. Some say Mondale would have won without them.

Since that time, a Democrat has won the nomination early enough where the superdelegates haven’t mattered.

We rate this claim Mostly True.