Now the planning commission, like the Commission of Fine Arts, which approved the project last month, is made up of people appointed not on the basis of expertise — like the architects, planners and urban designers Mr. Trump fired to make way for them — but for their willingness to do the president’s bidding. As Rodney Mims Cook Jr., the classical architect who now heads the Commission of Fine Arts, said before it voted to approve the ballroom without even reviewing final plans, “This is an important thing to the president” that would “let the president do his job.”