Can Bernie Sanders really change the Democratic Party at the convention?

Bernie Sanders, fresh off a victory over Hillary Clinton in Indiana’s open primary, told reporters late Tuesday night that he believes he can pull off “one of the great political upsets in the history of the United States.”

Most political observers are deeply skeptical of Sanders’ claims, given the tough math facing the senator. Still, the grassroots candidate has his eyes on a different upset — he hopes to translate his strong showing in the primary into sweeping changes in how the Democratic Party works.

At July’s convention, which he insists will be “contested,” Sanders plans to get his key policy goals, such as a $15 minimum wage and a ban on fracking, into the party platform. His even more ambitious goal is to transform the way the Democratic Party picks its presidential nominee, to make it easier for a Sanders-like candidate to win in the future.

First on the agenda is changing the primary system in each state so that independents and even Republicans can vote to pick the Democratic nominee. Sanders has done much better in these so-called open primaries than in closed ones, which are limited to registered Democrats.

“I think clearly the convention and the Democratic National Committee can change the rules and can create a scenario that makes it clear that we want open primaries in 50 states in this country,” Sanders told the Washington Post last week. He also said it’s time for the party to “rethink” its superdelegate system. Superdelegates, who make up about 15 percent of all delegates and overwhelmingly back Clinton, can support whichever candidate they want.

But can Sanders, who did not identify as a Democrat until this past year, convince Democrats to change their own rules so dramatically at their convention? The Clinton campaign clearly does not think Sanders has as much leverage as he thinks he does.

The former secretary of state laughed when NBC’s Andrea Mitchell asked her on Tuesday about Sanders’ claims that the convention will be “contested” in July.

“He has every right to finish out this primary season. I couldn’t argue with that,” she said. She added Sanders will “be a part of” the convention’s mission to unify the Democratic Party and defeat Trump.

Meanwhile, Rep. Debbie Wasserman Schultz, chair of the DNC, said on MSNBC on Monday that if anything, she would prefer to change all 50 primaries to be closed, not open.

Democratic presidential candidate Bernie Sanders speaks during his “A Future to Believe In” rally in April at the Big Sandy Superstore Arena in Huntington, W.Va. (Sholten Singer/The Herald-Dispatch via AP)

“I believe that the party’s nominee should be chosen — this is Debbie Wasserman Schultz’s opinion — that the party’s nominee should be chosen by members of the party,” she said.

Sanders not only faces Democratic establishment resistance to his plan, but also he will likely go into the convention with far fewer delegates than Clinton — a simple but important hurdle.

“He who has the gold makes the rules,” said Matt Dickinson, a political science professor at Middlebury College. “And right now, the gold is how many delegates you have.”

There’s also the problem that the convention is usually not the place where major primary rules changes happen. “Reforming the rules for the next primary season four years from now will probably not happen in a major way at the convention,” said former Vermont Gov. Howard Dean, a superdelegate who backs Clinton. “The Democrats generally make their rules two years ahead with a rules committee put together largely by the president’s people if there is a Democratic president.”

Dean added that changing the primaries to be fairer is difficult because states can be stubborn about their processes. “Caucuses are even more undemocratic than closed primaries because they discriminate against Americans stationed overseas, the infirm and disabled, those in nursing homes, etc. Try getting caucus states to give up their status,” Dean said.

The former governor said it’s far more likely that the Democrats would rethink the role of the party’s superdelegates. Superdelegates, who are mostly made up of party officials and politicians, were created to act as a check against nominating a candidate too liberal to win general elections. But they’ve never functioned that way, instead just backing the candidate who won the most pledged delegates in each election. A move to officially change the rules so that superdelegates function the same as pledged delegates may gain traction. Delegates could appoint a committee to look into those changes at the convention, or pass a nonbinding resolution to change that process.

Sanders is also in a bind because he’s already promised to support the Democratic nominee in the general election no matter what. Clinton has been reminding him of this fact in recent interviews. “He also said he’ll work tirelessly seven days a week to defeat Donald Trump,” Clinton said on Tuesday.

That means that if superdelegates don’t go along with his plan to flip their votes to him since Clinton will almost certainly have won a majority of pledged delegates and the popular vote, Sanders will need to follow his promise to back Clinton. That gives him little leverage to demand major rules changes. Even if he doesn’t get major concessions from the party, he’s already given his word that he’ll back her.

Still, Clinton wants Sanders’ enthusiastic support and cooperation to help her in the general election. Sanders outraised Clinton for several months in a row this year, and amassed a valuable donor list of 2 million. He could also lend Clinton a hand among younger and white male supporters, constituencies she has been weaker with during the primary season.

The convention is also an opportunity for the DNC and Clinton’s campaign to soothe some Sanders supporters’ complaints that the system itself has been unfair to the senator. They have charged that the DNC cannot be fair to Sanders since Clinton’s fundraising provides about one-fifth of the group’s budget and its chair, Wasserman Schultz, was a key figure in her 2008 campaign. Conceding key points to Sanders could bring some of his independent supporters in as Democrats.

Sanders has not made it explicit whether he will push for a convention-floor fight on the rules or if he’ll just demand his fair share of delegates on the platform writing committee and other committees. Sanders’ top strategist, Tad Devine, did not respond to a request for comment about the team’s strategy.