U.S. Sen. Angus King formally announced his re-election run Wednesday, saying he thinks he can help bridge the partisan divide in the Senate.

“I’m running again for the Senate for two main reasons,” he said in a video posted to social media. “One is, there’s a lot left to do. The second is, we’re losing the middle in the Senate.”

King, 80, who is an independent, is seeking his third term in the Senate following eight years as governor. He faces three challengers — former Maine Republican Party chairwoman Demi Kouzounas, Democrat David Costello of Brunswick and independent Jason Cherry of Unity.

The Maine Republican Party wasted no time attacking King following his announcement, sending an email blast urging donors to help raise money to defeat him.

Kouzounas also released a statement, saying Maine needs a problem solver in the Senate.

“Our families are grappling with rampant inflation, a housing crisis, and ongoing border security issues," she said. "Maine deserves a Senator who won't just talk about problems but will roll up their sleeves and solve them."

King has been raising money for months ahead of the formal announcement. In his video, he said Congress has taken important steps to fund infrastructure bills and those that benefit veterans.

“A lot of the people who were at the heart of making those deals, making those compromises are either gone or are leaving the Senate,” he said. “I’m running because I think I have a role to play to bridge the divide, to listen to people, to bring people together, and to compromise on these difficult issues.”

King won his first Senate election in 2012 by winning 53% of the vote in defeating Democrat Cynthia Dill and Republican Charlie Summers.

In 2018, he earned 54% of the vote against Republican Eric Brakey and Democrat Zak Ringelstein.