Amtrak is losing lots of money, so what to do? How about spending $151 billion to build a 10 mile tunnel under Philly

Why a tunnel is necessary is hardly obvious to me.  I have traveled that route by train many times, and I don't see how a 10 mile tunnel will improve service very much.  From The Economist:  

And all this is for marginal improvements in speed and access. The tracks around and through Philadelphia aren't, generally, big obstacles to high-speed rail—the tunnels in and around Baltimore, Maryland are. It would be much cheaper to replace Baltimore's terrible tunnels than to build a fancy new one under Philadelphia. . . .

Of course, Amtrak has all sorts of other ways of spending taxpayer money.

The Philadelphia tunnel, unfortunately, isn't even the worst part of Amtrak's plan. That honour goes to a $7 billion renovation of Washington's Union Station (pictured), which Slate's Matthew Yglesias rightly calls "insane". Amtrak's cost estimate is many times higher than for similar projects in Europe. . . .