“The campaign is just hyper-focused on whites in Iowa and African-Americans and it placed less value on Latino outreach,” an immigration activist and friend who spoke with her told POLITICO.

“Vanessa kept banging her head against the wall trying to get them to take the community more seriously,” the friend, who wasn’t authorized to speak on her behalf, said. “And Biden just really won’t change when it comes to the way he talks about immigration. It became too much.”

The resignation of Cárdenas, an activist who has never worked on a political campaign before, does not leave Biden without a Latino outreach team. Cristóbal Alex, former president of the influential Latino Victory Fund, remains Biden’s senior-most adviser for issues involving Hispanic voters. And, though Cárdenas worked with coalition groups, Biden has a Latinx outreach director, Laura Jiménez.

Cárdenas’ departure is the latest in a string of troubles Biden’s campaign has had with Latino and Hispanic leaders and groups, a tension partly rooted in the fact that the candidate has held firmly to formerly centrist Democratic party positions on immigration even as activists have grown more vocal and progressive.

But for all the criticism, Biden continues to lead among Latino voters in many national polls and surveys of states with heavy Hispanic populations. In other polls of Latinos, Biden is essentially tied with Vermont Sen. Bernie Sanders.

Biden was criticized for skipping a Latino elected officials forum in June — at the time, a campaign surrogate held up Cárdenas’ role in the campaign as proof of Biden’s commitment to Latino voters. And in August, his campaign went into damage control after immigration activists grew upset with him over how he spoke about the issue at a debate. He also avoided a California Democratic event where he was aware the immigration issue could haunt him.

At a South Carolina event on Thursday, Biden ended up in a widely publicized clash with Carlos Rojas, an immigration activist with the group Movimiento Cosecha, who wanted the candidate to pledge to halt deportations.

"No. I will not stop all deportations. I will prioritize deportations, only people who have committed a felony or serious crime,” Biden told Rojas.

Rojas then told Biden that he had volunteered for the Obama-Biden campaign in 2008 but became disenchanted with the Obama administration because “over those 8 years, there were 3 million people that were deported and separated from their families.”

“You should vote for Trump,” Biden cut in.

The exchange, which occurred after Cárdenas had quit, underscored her concerns with the campaign, a second friend told POLITICO.

“What happened last week was a perfect example of what Vanessa was dealing with,” the friend, who was also not authorized to speak for her, told POLITICO. “Biden just refuses to talk about the issue in a compassionate way.”

