Difficulty: railroad pensions are some of the only half-decent ones left in the whole country, and a lot of these workers will take a big hit on their retiremen

Difficulty: railroad pensions are some of the only half-decent ones left in the whole country, and a lot of these workers will take a big hit on their retirement for leaving early (years of delay in when the pay-outs start, much smaller amount than if they'd finished at the RR, et c.) This lock-in give the companies more leeway to abuse the workers if the unions are prevented from functioning to protect them. Which is what's happened thanks to Congress throwing the workers under the bus.