Ever since Steve Bannon was brought on board to serve on Donald Trump's campaign last summer, backlash quickly resulted due to the former Breitbart News CEO's controversial reputation. While many have spoken out against Bannon, one Hollywood movie star has taken his criticism to another level.

Penn on Bannon

Back in 1991, actor Sean Penn made his directorial debut with the film "The Indian Runner," starring Viggo Mortensen, Patricia Arquette, Charles Bronson, and Dennis Hopper. Serving as an executive producer on the film was Steve Bannon, who would later invest in the hit TV show "Seinfeld," before taking on the role of running the right-wing news site Breitbart News.

In recent years, Bannon has been linked to far right-wing politics in the United States, pushing back from more establishment Republicans to pull the GOP in a more extreme direction. Critics of Bannon have gone as far as to label him a "white nationalist" and a "racist," though he has repeatedly dismissed the allegations against him. After Donald Trump pulled off the upset and picked up the win on Election Day, Bannon was brought over to the administration as the chief strategist. However, recent reports say that Bannon could soon be on his way out, with Trump siding with son-in-law Jared Kushner in the apparent feud between the two men. As reported by Death & Taxes on April 8, Penn elaborated on his time with Bannon, and didn't hold back his thoughts.

During his interview with Death & Taxes, Sean Penn described his time with Steve Bannon during production of "The Indian Runner." "Bannon was then, as he is now, simply another bitter Hollywood wannabe who went rogue by way of toxic narcissistic iconoclasm," Penn said of the former head of Breitbart News.

Not stopping there, Penn went on to describe Bannon as a "hateful bloated punk" who deep down inside "despises mankind."

Bannon trouble

Last week, Donald Trump removed Steve Bannon from his spot on the National Security Counsel, which didn't go over well with the chief strategist.

Bannon reportedly threatened to quit the administration completely, but the former host of "The Apprentice" called his bluff. As of press time, Bannon is still employed, though various reports on Friday noted that Trump is looking to make a major shake-up, which could include a new chief strategist, as well as replacing Reince Priebus as Chief of Staff. With Trump only in office for just over two months, it appears that there is enough trouble behind the scenes to cause the president to reshuffle his entire administration.