Vermont Sen. Bernie Sanders and the leader of "the Squad" are reportedly not seeing eye to eye on the campaign trail.

New York Rep. Alexandria Ocasio-Cortez is reportedly frustrating the Sanders campaign during her appearances at the socialist's campaign rallies. While Sanders was occupied in the Senate during the impeachment trial of President Trump, AOC subbed in for him. However, she did not mention the candidate by name during a January rally, though she endorsed him last October.

Vanity Fair reported that Sanders's campaign manager, Faiz Shakir, expressed his frustration to AOC's campaign manager over texts, saying her immigration stances were too extreme. “Organizing is about tipping people off if you start to see that ICE and CBP are in communities, to try and keep people safe," she said at an Iowa rally. “I’m not here to reform some of these systems when we talk about immigration. I’m here because Sen. Sanders has actually committed to breaking up ICE and CBP. That’s why I’m here," she added.

Some in the Sanders campaign were reportedly frustrated by AOC's comments discouraging cooperation with federal authorities, saying they were off-track of Sanders's stance, which opposes "open borders."

AOC's team was also reportedly frustrated with Sanders's acceptance of comedian Joe Rogan's endorsement. Following blowback, Sanders's spokeswoman distanced the campaign from Rogan but noted that the campaign will need a "big tent" of supporters to defeat Trump.

"The goal of our campaign is to build a multiracial, multigenerational movement that is large enough to defeat Donald Trump and the powerful special interests whose greed and corruption is the root cause of the outrageous inequality in America. Sharing a big tent requires including those who do not share every one of our beliefs while always making clear that we will never compromise our values," she told the Hill.

"The truth is that, by standing together in solidarity, we share the values of love and respect that will move us in the direction of a more humane, more equal world."

In addition to AOC's endorsement, Sanders is being supported by Minnesota Rep. Ilhan Omar and Michigan Rep. Rashida Tlaib.