I'm no fan of Biden (though I did and will vote for him) but that's not what happened. He did not bust the unions, the 12 unions still exist. He broke a strike, which is the intended purpose of the Railway Labor Act of 1926.

The law he put before congress to force a resolution to the three year negotiation deadlock would have guaranteed the workers 7 days of sick leave per year (they wanted 15). It passed the House but the Senate knocked it down to 1 day, with a 14% immediate pay increase and an additional 25% over the next five years.

Biden continued negotiate for the unions to get the sick days. They don't all have them yet, but at this point 61% of the workers do have 4 short notice paid sick days with the option to trade three personal days for an additional 3 short notice sick days. Negotiations are still happening, the Biden administration is still part of them.

The Ohio derailment disaster was not a result of worker error (or lack of sick days) but lack of maintenance regulations, which was not something that was being negotiated at that time.

https://en.wikipedia.org/wiki/2022_United_States_railroad_labor_dispute

https://www.reuters.com/business/white-house-renews-pressure-railroads-over-paid-sick-leave-2023-02-09/

https://www.reuters.com/world/us/most-unionized-us-rail-workers-now-have-new-sick-leave-2023-06-05/#:~:text=Under%20the%20agreement%20effective%20Aug,use%20as%20paid%20sick%20time.&text=Our%20Standards%3A%20The%20Thomson%20Reuters%20Trust%20Principles

Beau of the Fifth Column, Let's Talk About Biden, the Rails and Sick days... Youtube link

I just thought union busting was something of a proud American tradition.

2 is kinda irrelevant in the context of the election though. If you think Biden supports them too much wait until you see the alternative. Trump doesn’t strike me as the kind of guy to say “Palestinians need our help”. He strikes me as the guy who’ll say “See? This is why I’m writing a new Muslim ban”