In 1981 federal air traffic controllers went on strike citing long hours and low pay after rejecting a contract put forth by the FAA, their employers. The President at the time was Reagan who was very much on the side of management and publicly stated that those who were striking were violating their contract and would be terminated. The US federal government was the boss in that situation and could fire at will any employee. About 11,000 people were fired and this set a precedent.

With the current rail strike it’s a little different. The workers are not federal employees but do work in an absolutely essential industry. Thus, any disruptions to the industry would result in a national emergency with food rotting, goods remaining at factories, imports and exports halted, etc. In a national emergency, our government has nearly limitless power (see Bush’s “wartime” presidency and the invasion of Iraq) and the Biden administration is using the inevitable emergency declaration if a strike occurs to step in now and try to mediate a deal. They brokered a deal between management and union leaders that favored the management position and only includes one scheduled day off per MONTH (you get at least 8 from weekends in any other industry) and said that’s the best we can do. Union leadership is forced to bring it to a vote amongst members which is getting rejected as we speak. So, they’re going to strike and it will be a huge test to the Biden presidency with most likely an opposition controlled legislature whether he will follow in Reagan’s footsteps to crush the strike and force people to work under those conditions or come down on management and revoke their federal contracts unless they give in to the workers.

I know this is a long answer and has a lot more background info than you probably though you needed, but it all boils down to our federal gov’t has historically been in favor of business interests and has heavily legislated and governed in that manner for the last 40 years after Reagan and his handling of the PATCO strike.