If you dig deeper (sorry) into the tunnel story, you find that it's another one of those wicked huge projects (sound like some others of note?) that will be very beneficial for travelers (direct connection between LIRR and Metro-North and subways at Grand Central Terminal, has been on the books for decades if not longer and under construction for near a decade, includes much more than just a tunnel, and could have the cost only approximately estimated until work got started because there was no way to tell (even in a place as well-explored underground as NY) exactly what they would find until they got into the hole. It's close enough to being done now that there's no purpose served (other than to maybe finding somebody sacrificial - probably not at the top - to put in jail for fiddles) in trying to stop it.

Tunneling is like that. You can poke all the test holes and do all the geologic studies you want, but it's just not possible to KNOW what's happening until you get into the ground with the Big Hole(s). That's why I think the cost estimates for any of the routes for CAHSR between Bakersfield and LA, and between the Central Valley and SJ/SF for that matter, are just so much smoke at this stage. But if you want the train (whether under the current management or otherwise, including Hyperloop), you have to deal with uncertainty and tunnels. And you'll need a pretty deep pocket for inevitable overruns if the initial budget is politically acceptable (not big enough).

Obviously some people don't want HSR, or any passenger train really, - they're happy with cars, or maybe horse & buggy. 3rd World all the way is the mantra. Sorry, I'd like to at least see my kids in second place if not better, and that requires alternatives to driving and flying for intermediate distances alias trains of decent, if not the highest, speed and buses.

Amtrak will never go over the Tehachapi mountains on the current railroad line; it's too busy and slow, even if (ha!) the current owners would let it. But even if there's no HSR Amtrak eventually will need to go there - buses on I-5 won't work forever. HSR, even if re-focused as electrified Amtrak pumped up to, say, 125 mph, that ends at Bakersfield throwing the passengers on buses, makes no sense unless Ecotopia (separation from the US without SoCal) actually happens.