Joe Walsh said he lost his national radio show after announcing his campaign for president.

The former Republican congressman from Illinois told CNN on Monday he does not know why he was let go, but said most of his audience supports President Trump.

"I just got a notice before I came in the studio. I'm running for president. I oppose this president. Most of my listeners support the president. It's not an easy thing to do to be in conservative talk radio and oppose this president. And I knew that, John, when I made the announcement yesterday, that it could be in jeopardy," he told guest host John Berman.

Walsh said he believes that "80 to 90%" of his audience supports Trump.

Radio Ink reported earlier in the day that Salem Radio Network was canceling national distribution of Walsh's radio show.

Walsh announced on Sunday he will be challenging Trump for the 2020 Republican nomination.

Walsh has faced questions about his past incendiary remarks, with many of them directed at former President Barack Obama. His use of racial slurs got his show briefly kicked off the air in 2014. Now he claims Trump's brash demeanor helped him realize the error of his ways.

During his interview on CNN, Walsh was asked about how policy positions. Walsh mentioned border security and building a wall along the U.S.-Mexico border.

Walsh, who supported Trump in the 2016 election, said it was a "difficult thing" to decide to run for president, but he believes "it's urgent because this president is a danger. We cannot let him get elected for another four years."