A Florida man is behind bars for allegedly threatening to murder the children of a Republican congressman amid the national debate over immigration policies.

The suspect is Laurence Wayne Key of Stuart, Florida, who is reportedly active with the Martin County Democratic Party as well as Planned Parenthood.

The congressman is U.S. Rep. Brian Mast, who represents the South Florida district in which Key resides.

According to WPTV, a criminal complaint indicates Key allegedly phoned Mast's Washington, D.C. office Monday, telling an intern: "I'm going to find the congressman's kids and kill them. If you're going to separate kids at the border, I'm going to kill his kids. Don't try to find me because you won't."

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The FBI was notified and Key was arrested a short time after the investigation began.

Key reportedly told the FBI and a Martin County deputy he did not threaten to kill Mast's children, but explained that if the congressman supported the immigration policies of President Trump, Mast should be separated from his own children.

But when police specifically asked the intern who took the call how certain he was that the word "kill" was used, the intern said "100 percent" and then "150 percent."

According to the criminal complaint, Key contacted Mast's office 478 times. He also contacted the offices of two other lawmakers on Monday, U.S. Sen. Marco Rubio, R-Fla., and U.S. Sen. Bill Nelson, D-Fla.

On his social-media pages, Key is politically active, volunteering for the local Democratic Party, and his Facebook cover photo expresses love for Planned Parenthood.

Friends reportedly call the suspect a "gentle soul," not believing he would hurt anyone.

Radio talk-show host Rush Limbaugh cited Key's arrest as part of the media's influence on Americans, prompting some to get violent.

"You've got the media driving people crazy," Limbaugh said. "They've already begun shooting Republicans at baseball practice, [for example, Congressman] Steve Scalise."

U.S. Rep. Steve Scalise, R-La., was wounded last year when he was shot by a fan of the leftist Southern Poverty Law Center, which described Scalise as a white supremacist.

Limbaugh noted immigration "remains the focus of all these deranged leftists trying to get Trump."