Bernie Sanders has the internet to thank for invigorating his energetic, youth-driven, grassroots presidential campaign. But the internet has also created a host of problems for Sanders’s campaign, problems also known as the Bernie Bros.

The Vermont senator has tried to distance himself from the anonymous trolls who swarm and attack anyone remotely critical of his campaign. Sanders denounced the “vicious” tactics some of his online supporters have used after they went after members of Nevada’s Culinary Union. And he has since tried to downplay the significance of his most aggressive keyboard warriors.

But as it turns out, the Bernie Bros’ toxicity is present inside Sanders’s campaign too. Using a private account, Ben Mora, the regional field director for Sanders’s Michigan team, regularly attacked Sanders’s Democratic opponents, according to the Daily Beast. He described Minnesota Sen. Amy Klobuchar as “pained” and “chunky,” referred to Pete Buttigieg as “what happens when the therapist botches the conversion,” and called Massachusetts Sen. Elizabeth Warren a “dumb Okie” and “an adult diaper fetishist” who “looks like shit.”

These comments are troubling but not surprising. Last month, another Sanders field organizer in South Carolina, Martin Weissgerber, was caught praising gulags and arguing that Sanders should “send Republicans to reeducation camps.”

Sanders’s Iowa field organizer, Kyle Jurek, made similar comments last month and even warned that if Sanders doesn’t win the nomination, “F---ing Milwaukee will burn. It'll start in Milwaukee, and, then, when they f---ing — when the police push back on that … the cops are going be the ones that are getting f---ing beating in Milwaukee.”

Sanders is not responsible for the actions of his supporters. And it’s important to note the Bernie Bros do not represent the entirety of Sanders’s base. But this has been a problem for far too long. The vitriolic harassment was present in 2016 when Sanders lost the nomination, and it has become worse this time around.

The duration and frequency of this online harassment suggest this is more than just the angsty musings of a few online trolls. This is a deep-rooted mindset, one that viscerally despises those who oppose the revolution Sanders’s base supports and one that has now worked its way into the heart of Sanders’s campaign.