Moore's defeat means Republicans' Senate majority narrows to 51-49 at a time when they've had difficulty moving major pieces of Trump's agenda and Democrats are starting to convince themselves that they have a shot of winning control next year.
"After Alabama disaster GOP must do right thing and DUMP Steve Bannon", King, a Seaford Republican, said in a tweet shortly before 7 a.m.
In an interview on CNN's "New Day" Wednesday morning, King took it further.
The Republican House Representative from Long Island who did not hold back, putting his critique of Bannon in a broader context, saying "It's not a political issue but a moral issue", adding "this guy does not belong on the national stage".
"He sort of parades himself out there with his weird, alt-right views he has, and to me it's demeaning to the whole governmental and political process", King said. "I think last night Alabama...was a revulsion at people at his style, at his type of divisive views".More news: Once again, Grand Rapids police point guns at a Black child
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Meghan McCain, the outspoken media pundit and daughter of Sen.
Rich Lowry, the editor of the conservative National Review, said the Republican defeat in Alabama should be a lesson to other states where Bannon "wants to run a fringy candidate".
Bannon, President Donald Trump's former chief political strategist and right-wing firebrand, backed Roy Moore during his unsuccessful bid for a Senate seat in Alabama.
The Senate Leadership Fund also released a statement blaming Bannon for the shocking blow to the party's grip in the Senate.
The president endorsed Moore eight days before the election, appeared at a pro-Moore rally in Pensacola, Florida, four days before the election, and raised doubts about the sexual misconduct allegations against Moore.