"All ads must be congratulatory in nature. The Washington Post reserves the right to reject any notice."
For those of us paying attention for at least the past decade or so, this isn't surprising. But consider the Orwellian notion of an ostensibly bias-free press organ requiring its readers' messages to a politician to be positive or be rejected. One can understand why, on the occasion of his inauguration, the Post would not want to be in the business of selling off space for rants against the man but then the question becomes...why do it at all?
At this point, feel free to humor yourself by imagining the Post offering paid congratulatory messages to an incoming Republican.