

Even if this is true, and I make no comment on that, you may very well be correct. Without further laws/treaties bidding ≠ selecting. I assume one of the criteria is the company’s fitness.
The train operators should recognise that they are in a bit of a monopsony, here.

Trump can raise all the executive orders he wants. He just doesn’t have jurisdiction on how states run their elections.
This doesn’t mean he can’t cause trouble, though. For instance, maybe he can just order the USPS to not deliver ballot mail. Or worse, open it an substitute the ballot inside to one that’s much more favourable to him.
Obviously, if he does that the US can kiss goodbye to being a representative democracy.