An immigrant-rights protester whose recent confrontation with former Vice President Joe Biden made headlines was hired this week by rival Bernie Sanders’ campaign.

Carlos E. Rojas, who previously helped lead Movimiento Cosecha, a left-wing group that advocates for undocumented immigrants, will be a Latinx community organizer in Iowa for Sanders. Rojas’ hiring prompted criticism among Biden supporters and some independent political analysts, who accused the Sanders campaign of promoting someone who has personally attacked a Democratic rival.

But Sanders supporters celebrated the hiring of Rojas, an experienced activist who previously volunteered on the Obama campaign. Sanders has a history of hiring activists to join his ranks. His deputy press secretary is an undocumented immigrant.

Biden and Sanders are on opposite ends of the political spectrum in the Democratic presidential primary, polling first and second in most surveys. While tensions between their supporters make sense for that reason, there’s also some overlap in their constituencies, especially among minority and working-class voters. In a Morning Consult poll released this week, one-third of Biden supporters said their second choice was Sanders, the independent, self-identified socialist senator from Vermont.

“As someone who is part of the immigrants rights movement, I believe Sanders has the most progressive platform when it comes to immigration, foreign policy and the best approach when it comes to basic needs like healthcare and education,” Rojas said in a statement on Facebook.

The Sanders campaign confirmed Rojas’ hiring Thursday and said he was not on the payroll when he disrupted a Biden rally in November.

At that event, Rojas drove down to South Carolina from Elizabeth, N.J., with an undocumented woman to challenge Biden on the three million deportations during the Obama administration. Biden initially engaged Rojas in debate, but when the exchange grew tense, Biden cut Rojas off and told him to “go vote for Trump.”

Movimento Cosecha also held a small sit-in protest at Biden’s campaign headquarters when the Philadelphia office opened in July.

In March, the Sanders campaign had to defend its hiring of a veteran investigative journalist, David Sirota, as senior adviser and speechwriter. Sirota had been blasting other Democrats on Twitter and in columns at the Guardian prior to his hiring.

The hires prompted critics to recall the fallout of the 2016 Democrartic primary, when Sanders lost the nomination to Hillary Clinton and some of his most fervent supporters exacerbated rifts within the party by continuing aggressive online attacks.

Sanders himself launched his 2020 campaign pledging not to attack, bully, or harass any fellow candidate.