You keep using the word "extortion." I don't think it means what you think it means.
He is limited to firing them w/o cause, or just make some bogus statement.
That statement totally undermines your position. So, the employer can fire you for consenting to a search so long as he doesn't tell you that is why he is firing you?
THat doesn't make sense. Once the employer mounts the extortion demand, the firing is connected. WIthout the extortion demand being made, all the employer can do is fire folks at random.