Labor leader Dolores Huerta attended a Nevada caucus to stump for Hillary Clinton — only to get shouted down, she and Clinton supporters said, by Bernie Sanders supporters chanting "English only" when she tried to offer a Spanish translation.

Harrah's casino site- Bernie supporters chant "English-only" to stop civil rights leader @DoloresHuerta from providing Spanish translation. — America Ferrera (@AmericaFerrera) February 20, 2016

I offered to translate & Bernie supporters chanted English only! We fought too long & hard to be silenced Si Se Puede! #ImwithHer #NVcaucus — Dolores Huerta (@DoloresHuerta) February 20, 2016

But several other people present at the rally, including some Sanders supporters, said people did not chant "English only":

Link to the entire vid. The translation ask starts at 53:30 & mod says English Only at 55:18. NO CHANTING. https://t.co/3bxIs9eKJy — Susan Sarandon (@SusanSarandon) February 21, 2016

@cin_d25 @SusanSarandon @AmericaFerrera I was also there. No one shouted English only except the moderator. I was very tuned into this. — Gaby Hoffmann (@gabymhoffmann) February 21, 2016

@AmericaFerrera @DoloresHuerta Also, & I noted this while there, the hill side was the one that applauded when he says english only. — Gaby Hoffmann (@gabymhoffmann) February 21, 2016

This video clip shows Sanders supporters shouting Huerta down. But the shouts aren't entirely distinct, and it doesn't prove that they were shouting "English only."

Sanders's campaign has not said anything about the incident.

Throughout his campaign, Bernie Sanders has faced accusations that he's not as in tune with the issues of racial justice facing much of the Democratic base as he is with them on economic issues. He's also faced accusations that his supporters, while enthusiastic about Sanders, are obnoxious, aggressive, and even harassing toward Clinton and her supporters.

Sanders and his campaign have fought admirably to address both of these concerns. But this is very bad for the campaign's relationship with progressive Latino activists. And, especially if the reports of "English only" chants are true, it could damage the campaign's outreach to Latino voters.

It's not just a rebuke to Huerta — who is one of the more iconic Latinas in American political and labor history — or to Latinos. It's a rebuke to the Sanders campaign's concerted effort to reach out to Latino voters in Nevada, including Spanish speakers.

Update: Added accounts from other people at the event.