I'd like to introduce you to what has happened historically when labor was met with the national guard. Whether or not this would happen in the modern era I cannot say.
I do think, in 2022, anything of this nature happening on US grounds would not go over well at all. See the counter example, such as the Kent State shootings[0] which lead to a massive public outcry. It would, from a PR perspective at a minimum, completely obliterate public support for the railroad companies & the government and immediately give it to the workers.
[0]: https://en.wikipedia.org/wiki/Kent_State_shootings