Nixon could have deregulated the railroads instead. But he didn’t.
Nixon regulated the railroads because they were all going bankrupt. He didn’t want to be the president who saw American passenger rail functionally cease (Eastern corridor, which is still the only profitable part of AmTrak would have survived) so he made AmTrak. And every president since then has kept the mistake. Slick Willy actually is the only one that came close to doing the right thing, he gave them a big subsidy increase that were supposed to use to either become self sufficient or close down with all subsidies ending in 5 years. But 5 years later was W and he didn’t have the guts to go through with it. Only thing Clinton did I ever thought was a good idea and it came to naught.