Angus King

In this Feb. 7, 2018 file photo Sen. Angus King, I-Maine, speaks about immigration on Capitol Hill in Washington. King, a former governor of Maine, caucuses with the Democrats and has a track record as a political moderate. He is being challenged by a Eric Brakey, a Libertarian-leaning Republican, and Zak Ringelstein, a member of the Democratic Socialists of America. (AP Photo/Jacquelyn Martin, file)