Adam Kinzinger is no stranger to controversy, as he is one of two Republicans on the House select committee investigating Donald Trump's efforts to overturn the 2020 election and the then president's actions leading up to the deadly January 6, 2021.

Kinzinger, along with nine other House Republicans, voted in January to impeach Trump for inciting insurrection. There were threatening voicemail messages left by apparent Trump supporters.

Representative Adam Kinzinger sits at a desk.
Rep. Adam Kinzinger of Illinois at the Jan. 6 committee hearing on June 23. (Bill O'Leary/the Washington Post via Getty Images)

Kinzinger said to take a listen to some of the calls. The threats are not unusual.

Audio of the profanity-laden messages is preceded by a warning that reads, "You are about to hear real voicemails and phone calls directed to the Office of congressman Adam Kinzinger." The video contains threats of violence. It is recommended that viewer discretion is not used. In order to learn about the legislative process, my interns, high school or college level, receive all phone calls and voicemails.

Threats of violence over politics has increased heavily in the last few years. But the darkness has reached new lows. My new interns made this compilation of recent calls they’ve received while serving in my DC office.

WARNING: this video contains foul & graphic language. pic.twitter.com/yQJvvAHBVV

Adam Kinzinger is a congressman.

You backstabbing a boy. One man told Kinzinger that the mother were sitting up there lying like a dog.

There will be protests in front of your house this weekend. One man says, "We know where your family is and we're going to get you, you little c**p."

Kinzinger was told by a third caller that he would swing for treason.

Kinzinger has continued to speak out against Trump and the mob of his supporters who attempted to block the peaceful transfer of power to President Joe Biden.

Kinzinger, who is not seeking reelection this year, regularly engages his fellow Republicans on social media, as he did on July 4 when he retweeted House Minority Leader Kevin McCarthy's initial reaction to the January 6, 2021, riot at the U.S. Capitol

The January interview with Yahoo News was six months before the first public hearing of the select committee.

I'm sad of what the party has become. This is a party that always attracted me for the truth-tellingness, the kind of realism and the American strength aspect of foreign policy, the saying what needs to be said when it gets too big, etc. Kinzinger said that it's now a party that's profiting from populism and that it's focused on raising money. It's a sad moment. We need to keep fighting for the soul of it because it can be fixed over time. We are in a time where truth doesn't matter and this party will be around for a while. It's depressing to think that we're with it.