President Trump said Democratic megadonor Tom Steyer gave the impression of being a "crazed and stumbling lunatic" during an interview Sunday.

The comment comes days after Steyer, a Trump critic and potential 2020 Democratic candidate, was sent one of about a dozen pipe bombs mailed to prominent Democrats.

"Just watched Wacky Tom Steyer, who I have not seen in action before, be interviewed by @jaketapper," Trump tweeted following Steyer's appearance on Tapper's "State of the Union" program on CNN. "He comes off as a crazed & stumbling lunatic who should be running out of money pretty soon. As bad as their field is, if he is running for President, the Dems will eat him alive!"

Steyer, a California-based hedge fund manager, has spent millions of dollars on his "Need to Impeach" campaign, aimed at ousting Trump from office, as well as to boost Democratic candidates ahead of the 2018 midterm elections. He has not officially announced a 2020 bid for the White House.

While more than 6 million Americans have signed Steyer's petition advocating for Trump's impeachment, congressional Democrats have sought to distance themselves from his efforts out of fear they could alienate moderate voters.

When asked Sunday about the criticism, Steyer said polling indicated his views were in line with "most Americans."

"What we have is a movement that is asking for a different America, which is one that recognizes the rule of law, gets rid of corruption, and treats every American fairly," he said on CNN. "And if we're telling the truth and we're standing up for the American people, we're going to keep going."

Trump has come under scrutiny for adopting a bellicose stance against his political opponents, which critics argue has encouraged an increase in tensions across the country leading to a shooting at a synagogue in Pittsburgh on Saturday and bombs sent in the mail to Trump critics, including Steyer, last week.