Members of the media sit inside Wells Fargo Center on Saturday ahead of the Democratic National Convention in Philadelphia. (John Taggart/Bloomberg News)

The Democratic Party arrived here still divided over the results of its presidential primary season, with anger at the nominating process, the Clinton-Kaine ticket and hacked emails from the Democratic National Committee spilling into the party’s final meetings before the convention begins.

On each count, supporters of Bernie Sanders found new reasons to bristle about their choice in November. Hillary Clinton’s selection of Sen. Timothy M. Kaine (Va.) as her running mate angered progressives who had lobbied for someone from their movement. The partial failure of a push to end the use of superdelegates — the party activists and elected officials who are unbound by the primary results — dredged up feelings that the Clinton-Sanders face-off had not been fair.

And the leaked DNC emails, which showed party leaders writing off Sanders’s chances and speculating about how his religious views could hurt him politically, embarrassed Democrats who wanted to put the primaries behind them. Before the party’s rules committee began, Clinton supporter Donna Brazile could be seen walking over to Sanders campaign manager Jeff Weaver to say that nothing she wrote in the emails differed from what she had said in public.

“Certainly, someone should be held accountable for those emails,” Weaver said in an interview. “We spent days talking about who in the Trump campaign should be held accountable after a few sentences were lifted from Michelle Obama’s speech. Certainly, the DNC should be held at least as accountable as the Trump campaign.”

The rules committee, which typically approves the party’s nominating process with little debate, became an outlet for that frustration. Sanders’s supporters arrived with plans to end superdelegates altogether. Plan B was to compromise with Clinton supporters and reduce the superdelegates’ number or voting power. Plan C was to get enough votes on their amendments to demand a “minority report,” which could be voted on at the convention itself, with thousands of journalists watching.

The first plan failed, despite pleas and heckling from Sanders supporters who snaked around the hallway outside the meeting room and chanted “No more superdelegates!” and “Open the doors!” Inside the room, a smaller group chanted “Shame!” and “You’re killing the party!” as each amendment went down.

“If we walk out of this room with our heads hung low, affirming the status quo, that is going to be a statement to voters of this country,” said George Albro, a labor organizer and Sanders-backing member of the rules committee. “Do you want to walk out divided and to give Trump the ability to say we had an undemocratic election?”

Clinton supporters called for unity and dismissed the idea that the party’s rules were disenfranchising anyone. Former congressman Barney Frank, a Clinton supporter whom Sanders had wanted off the committee, presided over it with occasional notes of sarcasm.

“Listen to your voters!” yelled a Sanders supporter at one point.

“Oh, sorry — I wasn’t listening to you,” Frank joked.

Who will speak in Philadelphia during the 2016 Democratic National Convention

Other Clinton supporters argued that they were ill-equipped to decide the fate of superdelegates or that Sanders supporters, many of whom became active in politics only because of his campaign, didn’t appreciate the system.

“I watched Latino women and men rise up the ladder to become superdelegates; I watched African American men and women rise up that ladder,” said Rep. Sheila Jackson Lee (D-Tex.), a Clinton supporter. “We have never in any way skewed an election.”

Later in the evening Sanders supporters won a partial victory: A new “Unity reform commission” that would bind most superdelegates to the primary results, while allowing free votes for members of Congress, governors and party leaders, passed on a 158-to-6 vote. The Sanders supporters also won more than 50 votes on their key amendments — enough to demand a vote on the convention floor, which Sanders delegates intended to do.

“I feel like we lost the vote, but we won the debate,” said Diane Russell, a Maine state legislator who had been campaigning to end superdelegates by getting state parties on record against them.

In some ways, the Kaine pick was an even taller stumbling block. In interviews, a dozen Sanders delegates unanimously said they were not enthusiastic about Kaine; some admitted that they had never heard of him before.

“I think that Kaine is a wonderful guy, but this was an opportunity to reach out to progressives, and the opportunity was missed,” said Rod Halvorson, a Sanders delegate from Minnesota.

By Saturday afternoon, some Sanders supporters were exploring the possibility of putting an alternative to Kaine into nomination. National Nurses United, one of the first and largest unions to endorse Sanders, suggested that Ohio politician Nina Turner, one of Sanders’s most prominent black surrogates, run as a Kaine alternative. A loose alliance called the Bernie Delegates Network, which had polled members and found 88 percent opposed to Kaine, planned to hold a Sunday morning news conference.

“The outrage is not just smoldering — it is burning,” said Norman Solomon, a California delegate and leader of the Bernie Delegates Network. “There has been an insurgency in the party, far beyond anybody’s expectations. Hillary seems to have gone out of her way to say — not just to her delegates but to progressives — that she hasn’t learned anything from that insurgency.”

Sanders supporters who defended the Kaine pick did so tentatively and with the hope that Clinton picked him to turn out Hispanic voters. (Kaine is a fluent Spanish speaker.)

“There are other senators who would have been more helpful to her campaign, no doubt, but Tim is the pick now, and they need to focus on maximizing his strengths,” said Benjamin Jealous, a former NAACP president. “His strengths will only manifest if they focus on turning out the black and brown vote.”

But no Sanders supporter could find an upside in the DNC emails. During lulls in the rules meeting, they talked about the latest revelations from the emails, such as DNC Chairman Debbie Wasserman Schultz reacting to Sanders’s call for her ouster by saying he would lose the nomination anyway.

“It’s heartbreaking,” said Raisa Donato, a Sanders supporter who led a cry of “baaaa” to mock the people she labeled as the “sheep” voting to save superdelegates. “I had a lot of faith in our party, and that’s been challenged over the last week.”

Robert Becker, who ran Sanders’s campaign in Iowa, said he was personally offended by one of the leaked emails.

“Having run large organizations before, if my chief financial officer sent an email saying, ‘Hey, let’s attack a candidate on his religion,’ my reply-all wouldn’t have been ‘Amen,’ ” Becker said. “That’s what bothers me the most: The lack of professionalism and decency from the DNC in those emails, in going after Bernie Sanders.”

Weaver, who spent much of the day trying to craft deals on amendments, said that the emails “confirmed that Debbie Wasserman Schultz is really a divisive figure in the party rather than someone who can bring about unity against Donald Trump.”

In absentia, Trump was trying to prove that. “The Wikileaks e-mail release today was so bad to Sanders that it will make it impossible for him to support her, unless he is a fraud,” Trump tweeted Saturday afternoon. At the same time, Democrats in the rules committee — on both sides — were arguing that failing to support their positions would give Trump the presidency.

“You’re sending a message to all the people coming into the Democratic Party, who say: ‘Something’s not right here,’ ” said John Little, a Sanders supporters and rules committee member from Indiana. “That’s going to help Donald Trump.”