The problem comes from the fact that the US Senate is elected,
No, the problem comes from the fact that the U.S. government no longer considers itself bound to follow the Constitution. The rest of your post indicates what causes this problem. The legitimacy of the various parts of the U.S. government to do ANYTHING is supposed to come from the U.S. Constitution, not from "democratic legitimacy". The various states yielded their sovereignty to the federal government under the understanding that the federal government would be constrained by the Constitution, not free to do anything which was not opposed by the democratically expressed will of the people..
It would travel to your destination without ever having to stop.
Assuming of course that your destination is somewhere along where those rails run and that no one else is on those same rails and stopping between you and your destination,
There is no evidence to support that it is hard to fire minority employees.
Except of course for the fact that if you fire someone who belongs to a "disadvantaged" group (not just minorities), in most states they can bring you before a Human Relations Committee which will require you to prove that you did not fire them because they belonged to that group. They do not have to present any evidence that that was the reason they were fired.
Thus spake the master programmer: "After three days without programming, life becomes meaningless." -- Geoffrey James, "The Tao of Programming"