That's not the real problem. If it were, then there's a time-honored mechanism for clearing the way, eminent domain. To employ it, you need a politician with enormous political capital.

The problem is generating that capital. Most Americans simply don't care enough about transit for a politician running on the "Moar railways" platform to get elected.

Most of our passenger rail mass transit systems got built before reliable auto transportation became cheap. Now that cars are ubiquitous, the political will isn't there anymore.