If this quote from Mitch "The Turtle" Mcconnell were true wouldn't the SCOUTS be an elected position? Clearly it isn't and just as clearly there's nothing anywhere that says President's can't appoint justices to fill vacancies during there last year in office. The assertion there is takes the coincidence that no justices have recently died during the last year in office and elevates to some sort of rule that not found in the constitution or amendments.
“The American people should have a voice in the selection of their next Supreme Court justice,” Senator Mitch McConnell of Kentucky, the Republican majority leader, said in a statement. “Therefore, this vacancy should not be filled until we have a new president.”