Actor Hill Harper announced on Monday his plans to run for US Senate in Michigan to fill retiring Democratic Sen. Debbie Stabenow's seat.

"We can all feel it: D.C just isn't getting things done for people. We need representatives who'll take on special interests, get money out of politics, and make our government work for all of us. That's why today, I'm announcing my campaign for U.S. Senate in Michigan," he tweeted on Monday.

Harper, who is known for his role on "The Good Doctor" and hosted HLN's original primetime series "How It Really Happened," is running as a Democrat and will join a primary field that includes Michigan Rep. Elissa Slotkin, who announced her candidacy in February and is seen as a top contender.

Harper's campaign website touts him as a lawyer, actor, and single father. His announcement video is dedicated to his son, whom he adopted.

"You see the world you're growing up in doesn't feel like it's getting any better, it's getting more divisive and more dangerous. When you told me you were afraid to go to school because of shootings, that's not freedom. Our economy works for the richest while the most vulnerable have to work even harder than ever to keep up, that's not freedom," Harper said in his campaign announcement video.

"At the core of so much of this are too many politicians in office who don't really care about people," he added.

Michigan's Senate seat is crucial for Democrats, as it flipped from Donald Trump in 2016 to Joe Biden four years later. Democrats are defending 23 of the 34 Senate seats up for reelection next year, including three seats in states that backed Trump by at least 8 points in 2020: West Virginia, Montana and Ohio. Besides Michigan, the party is also defending seats in other battleground states such as Arizona, Nevada, Pennsylvania and Wisconsin.