A Democratic challenger to Lindsey Graham’s South Carolina Senate seat in 2020 formally announced his campaign launch on Wednesday.

In a comic book-themed video posted on Facebook, former South Carolina Democratic Party chairman, Jaime Harrison, highlights his humble roots in Orangeburg, S.C., and slammed Graham as “a guy who will say anything to stay in office.”

Harrison hammered down on Graham’s shifting stance on President Donald Trump, whom he called a “bigot” who was “not fit to be president of the United States” when the two faced off for the Republican presidential nomination in 2016. Graham has since been one of Trump's most consistent defenders.

“Lindsey Graham can’t lead us in any direction because he traded his moral compass for petty political gain,” Harrison says in the video. “He’s forgotten about the people he represents.”

Harrison, who was the state Democratic party’s first black chairman and served as an aide to Rep. James Clyburn, highlighted his “origin” story of being born to a teen mother, raised by his grandparents, and his education at Yale University and Georgetown Law School.

If successful, he would be the first Democrat to be elected to the Senate since 1998.

Graham, who is serving his third term, defeated his Democratic challenger in 2014 by more than 16 percentage points. Trump won the state of South Carolina over Hillary Clinton in 2016 by 14 percentage points.

The National Republican Senate Committee, meanwhile, slammed Harrison as a "looney liberal."

"Harrison is a looney liberal who was hand-picked to run by radical Washington Democrats," NRSC spokesperson Nathan Brand told CBS News. "Lindsey Graham is one of the most popular U.S. Senators in the country because South Carolina voters know that has delivered results and has been a tireless fighter for Palmetto State values."