Just a pedantic procedural point: The FCC is not an "agency", but a commission with 5 members. Once a commissioner is named, they cannot be removed by the President for any reason besides misconduct. The two of them besides Mr. Pai who are Republicans have been on for quite a while and their agreement is necessary for this scheme of his to work. He presumably has it, otherwise there would be no vote taking place, so it's not like this is merely a product of Trump’s unique intervention here.