Ron Chernow, chosen as the main guest at next year's White House Correspondents' dinner, publicly opposed Donald Trump's presidential bid and said he was "deeply disturbed" by the now-president's campaign.

In 2016, Chernow was part of a Historians Against Trump group and spoke out against the then GOP nominee in a Facebook video. His broadside against Trump lasted more than three minutes as he warned about threats posed to American rights, liberties, and traditions.

Chernow, author of an Alexander Hamilton biography that formed the basis of the hit musical, said in a 2017 C-SPAN interview he was drawn to Historians Against Trump by participation of other prominent figures including writer David McCullough and filmmaker Ken Burns.

“I was just kind of picking up things that I noticed were absent in Trump's words. Words of kindness and sympathy and compassion. There was much too much of an emphasis I thought on kind of money and power and strength,” Chernow said on CSPAN’s Q&A.

“Like many other historians, I have been deeply disturbed by the Trump campaign,” Chernow said, reading from a prepared statement. “More deeply disturbed than by any other presidential campaign in our history.”

Chernow concluded the video by imploring viewers, “Please, please, please folks — don’t let it happen here.”

The White House Correspondents' Association announced Monday that Chernow would perform at the April 27, 2019, event rather than a comedian. The 2018 performer, comedian Michelle Wolf, drew scorn in some quarters for her anti-Trump-administration remarks, including a joke mocking the physical appearance of White House press secretary Sarah Sanders.

Chernow won the 2011 Pulitzer Prize for Biography for his 2010 book about the life of former President George Washington. Prior biographical subjects include J.P. Morgan and John D. Rockefeller.

Trump has not said whether he would attend the 2019 White House Correspondents’ dinner. He skipped the first two dinners of his presidency but this year allowed staff members to attend.

Chernow did not immediately respond to a request for comment.