Just the sort of project Kick Starter was invented for.

When's the movie coming out?

A "Space Elevator" still seems a lot more feasible.

Wow....way to rip off the Jules Verne Gun Company.

I'm skeptical of space elevators, because they're stationary and eventually a satellite is going to ram the thing. Not to mention it's a delectable target for terrorists. Before I thought about the maglev approach, which would cost many billions, I'd consider building a large, very fast jet (reusable of course) as the first stage to get the second stage up to speed, and then release the spacecraft. I guess that's similar to what space-x is doing, but they just need a much bigger and faster initial stage. Hopefully scram jets will be developed before too long.

While fanciful, a project like this will be impossible to execute. There are too many stumbling blocks for something that requires 1,000 miles of surface tracks and an ungodly amount of electrical current.
What might be more feasible would be a "hybrid" system that has a few miles of track sloping up a mountain to 5,000 MSL with a conventional rocket taking over at release. Such a system might accelerate a rocket to several hundred MPH instead of escape velocity. That would reduce the cost of the entire system to something reasonable. It would also fit on an existing military reservation.
I think the actual solution to exorbitant launch costs is what SpaceX is constructing: A 100% reusable space launch system.

There are too many reasons why this specific concept wouldn't work. The very notion of building a 12 mile high structure to eject a small spacecraft is not feasible engineering. For comparison, the Burj Khalifa is 829m tall (0.51 of a mile), and the biggest force it has to withstand is side-loading from the wind, which can be even higher than it's own footprint weight on the ground. Magnetic levitation does not solve this problem, and 12 miles is only 63,000ft, well short of the 62 mile / 327,000ft Karmann line.
The space elevator concept might be better, where if you built it high enough, eventually you can have the structure in centrifugal tension due to the earth's rotation, but the forces resulting from the winds would dictate an impossibly high tensile strength requirement.
Bob Tackett has the right idea - the mother ship with space-plane concept like Space Ship 1 white knight 2, but on a larger scale. This is the most cost-effective and most efficient approach.

While it might be possible to build, the cost estimate is a joke. California's paying 65-100 billion for a few hundred miles of high speed rail - just normal steel rails. There's no way they'll get 1000 miles of superconducting rail in a vacuum sealed tube for 60 billion.

Even starting at a height of the highest mountains doesn't get us half way to 12 miles up. But since non-living things could withstand more Gs, why not a lower altitude, faster version of this for raw materials ane equipment? People can rendezvous later using the mothership approach. Or add some propolsion to counteract all the Gs of exiting the tube at a lower altitude. This might not be feasibile, but you could go faster (at a lower altitude) but gradually introduce the atmoshpere after it exists, by extending the tube and letting in controlled amounts of air, until it matches outside atmosphere. And instead of 1000 miles in a line, why not do it in a repeating circle, electronically controlling the amount of magnetism until launch speed is reached, and then switch the track (like a train) to the escape track. Bottom line - I could build my version of this for $20 billion! :-)

A 1000 mile long, 12 mile high track doesn't seem feasible, as others commenters have noted.
However, if the payload was limited to cargo, much higher g's could be used. Then, the runway could be significantly shorter. The runway could be further shortened with coryatjohn's "hybrid" system. Now, we may have a system that is (1) feasible not only in terms of construction but also for maintenance and security and (2) commercially competitive. Perhaps, even new possibilities for ground-to-ground cargo transportation.