They failed to deliver! No matter what else comes of this, we can take comfort in that.
The Post Office can grant an employee's request for leave without pay for any reason at all. There's nothing illegal about that. But when the Post Office is colluding with the public employee union to approve gobs of them, all at once, all to benefit a particular political candidate who just happens to be the preference of the union, that's a violation of the Hatch Act.