Senate Minority Leader Harry M. Reid said the unrest among Sen. Bernie Sanders’s presidential campaign supporters at Saturday’s Nevada Democratic Convention constitutes a “test of leadership” for Sanders, who until Tuesday remained silent on the chants, boos and threats that disrupted the event.

Reid (D-Nev.) said he spoke to Sanders Tuesday about the uprising at the Las Vegas convention Saturday, where Sanders supporters shouted down party officials and supporters of Hillary Clinton’s presidential campaign over the perception that the delegate selection process was tilted in Clinton’s favor. The state party headquarters was subsequently defaced with pro-Sanders graffiti, and the state party chairwoman reported receiving personal threats.

“I laid out to him what happened in Las Vegas,” Reid said. “I wanted to make sure that he understands, that he heard what went on there — the violence, and all the other bad things that has happened there. He said that he condemns that, and I’m confident he does. I’m confident he will be saying something about it soon. This is a test of leadership as we all know, and I’m hopeful and very confident that Senator Sanders will do the right thing.”

Shortly after Reid addressed reporters, Sanders issued a lengthy, largely defiant statement that included a commitment to “non-violent change” and a condemnation of “any and all forms of violence, including the personal harassment of individuals.” But it also faulted “the Democratic leadership” in Nevada for having “used its power to prevent a fair and transparent process from taking place.”

“The Democratic Party has a choice,” Sanders said. “It can open its doors and welcome into the party people who are prepared to fight for real economic and social change – people who are willing to take on Wall Street, corporate greed and a fossil fuel industry which is destroying this planet. Or the party can choose to maintain its status quo structure, remain dependent on big-money campaign contributions and be a party with limited participation and limited energy.”

Reid was among several Democratic lawmakers who reacted with dismay over the way the Paris hotel ballroom erupted over disputes over the rules governing the qualifications of delegates. Some expressed fears that the disorder at the convention in Reid’s home state could lead to similar unrest that could mar July’s Democratic National Convention in Philadelphia.

“It sets off an alarm bell that a small percentage of the delegates could disrupt the convention in a way where we can’t really think about why this election is important,” said Sen. Barbara Boxer (D-Calif.) who appeared in Las Vegas as a Clinton surrogate and was subjected to chants and boos. “We’ve got a list as long as my arm of things we have to address. If all we’re addressing is how to keep a convention peaceful because a small minority of people are disrupting it, it’s very difficult, and it doesn’t bode well for the election.”

Sen. Richard J. Durbin (D-Ill.), the minority whip, called the threats and demonstrations in Nevada “unacceptable.”

“That’s a Trump trick from his early rallies, and the Democrats ought to stay away from it,” he said.
“I would encourage Sen. Sanders to tell his supporters: Be fervent in your support of my candidacy, but don’t cross that line. … I think he should be forceful and encourage those those are supporting him to stay within the bounds of reasonable discourse.”

While only one Democratic senator, Jeff Merkley of Oregon, has endorsed Sanders, most of the others have given Sanders a wide berth to wage his campaign and have refrained from sharply criticizing him, even as his path to the party nomination has narrowed.

But there were new signs Tuesday that patience might be fading. “It’s my real hope that Sen. Sanders will convey to his supporters the importance of respecting the process,” said Sen. Chris Coons (D-Del.).

Boxer called on Sanders to “assert his leadership” and urge his supporters to maintain calm. “I think Sen. Sanders could really make a big difference if he gave a major speech to his supporters — they have a great communication network — and just told them, you know, that we’re all in this together. We’re all Democrats, and we need to take the high ground and not argue with each other. It’s hard to win an election when you’re not unified.”

Asked if she felt threatened at the event, Boxer replied, “I would say I feared for my safety. I don’t want to use the word threatened.”

The Nevada Democratic Party on Monday filed a formal complaint with the Democratic National Committee’s Rules and Bylaws Committee, accusing the Sanders campaign of a “penchant for extra-parliamentary behavior — indeed, actual violence — in place of democratic conduct in a convention setting.”

The Nevada party’s chairwoman, Roberta Lange, has been targeted with threats send to her personal phone, many of them vulgar and some threatening violence.

Ahead of the convention, Sanders issued a statement thanking his supporters for an “honest and dignified discussion of the issues” facing Americans.

“We share a commitment to electing progressive Democrats up-and-down the ballot in Nevada and across the country and are committed to soundly defeating Donald Trump and the right-wing Republican agenda. Working together respectfully and constructively on Saturday at the Nevada Democratic convention will move us closer to those essential goals,” he said.

Sanders has not addressed the unrest since it occurred Saturday.

Sen. Claire McCaskill (D-Mo.), an outspoken Clinton supporter, declined to blame Sanders himself for the upheaval and said she was confident the party would unite against presumptive Republican nominee Donald Trump.

“I think we’ve got to come together, and I think we will,” she said. “And I think Bernie will be a key part of that. We’re all confident that Bernie cares just as much about keeping Donald Trump out of the Oval Office as everyone who is supporting Hillary does.”

Correction, 5/18: An earlier version of this article incorrectly reported that McCaskill has called on Sanders to wind down his campaign. She has called on Sanders to tone down his personal attacks on Clinton but has not called on him to withdraw.