The biggest threat to CA high speed rail is NIMBYism dragging out the project and creating onerous requirements.

This isn't unique to rail, either - if a Hyperloop was built, it'd be NIMBYed just as badly.

CA isn't the only state investing in high speed rail. Elon musk lied to many people in many states with his Hyperloop project.

The entire country can be characterized by this quote.

What's the biggest threat to the USA?