The hosts have persistently criticized the polygraph tests that are required of anyone who is applying to become a border agent, saying they take too long, are often confrontational in tone and fail far more people than similar tests carried out by other federal agencies.

They have labeled reporters who cover topics in a way they do not approve as activists. Chris Cabrera, vice president of Local 3307 in Texas’s Rio Grande Valley, once accused Jorge Ramos, the Univision anchor, of having a vendetta against Mr. Trump. Fox News correspondent William La Jeunesse, on the other hand, has received warm welcomes in his appearances on the show.

They have also railed against the Obama administration’s hierarchy of priorities that forced border and immigration agents to focus on only deporting serious criminals. Then, they celebrated the new hard-line attitude by Mr. Trump.

“It’s a good time to be a Border Patrol agent right now,” the union’s president, Brandon Judd, said on Episode 143, released on March 9. “One thing that President Trump did that no politicians had done previous is he kept the conversation on the border.”

Mr. Del Cueto, who is also president of Local 2544, which represents 3,000 agents in the Tucson Sector, the Border Patrol’s largest regional division, replied, “He’s definitely kept his foot on the pedal.”

The union’s foray into podcasting began in July 2012, when it launched “State of the Union,” which focused on work matters.

“State of the Union” eventually merged into “The Green Line,” whose first episode came online on Sept. 23, 2014. Six months later, the podcast gained a major sponsor, Breitbart News, the conservative-leaning organization with an outsize influence in the Trump administration; its former executive chairman, Stephen K. Bannon, is a chief strategist to the president.