From the Washington Post:
“I was humbled to be considered for the Secretary of Energy position,” the senator said in a statement. “I have dedicated my life in public service to doing what is best for the people of West Virginia. Right now, I believe that I can best serve my state of West Virginia in the United States Senate.”
The Post goes on to speculate that Manchin will likely face competition for his senate seat in 2018 from Attorney General Morrisey or Congressmen McKinley or Jenkins.