While we're on the subject of major rethinking of the design philosophy for space launches...

At the moment, most launches are made from Florida to give a reasonably cheap (near equatorial) launch site and downrange safety.

That downrange safety clause leads to some interesting side effects. An early-launch engine failure leads to a need to abort the mission, which can safely be done anywhere by dumping debris in the (nearly) empty Atlantic. However, for shuttle missions it leads to a need for considerable cross-range* capability so that the craft can get down safely on one side of the Atlantic or the other.

*(Actually up/down range rather than cross range)

If missions were launched from the WEST coast, then a whole series of abort options would exist in the southern states which require only limited manouvring ability, leading to a safer vehicle (smaller or no wings, hence a better vertical stack with the spacecraft at the top, rather than vulnerably low down at the side) and more safe landing spots.

The downside would be safety to the general public on the ground, but IMHO, if there is a reasonable clear zone immediately downrange, then the danger to the general public would be not much greater than that posed from commercial and military airplanes that now and again drop out of the sky, especially if in-flight demolition was used to fragment the stack and combust its fuel.

Southern California looks good, with the extensive deserts inland of the coast, and the full width of the USA as a landing zone. Perhaps somewhere around the Salton Sea?

If the vehicle got far enough to go beyond North/South Carolina, then it should be sub-orbital and able to stretch to cross the Atlantic ballistically.

Even better, a leased facility on the east coast of Baja California, around 30 North, with aborts across Sonora, Chihuahua, Texas (including JSC, Houston), New Orleans and on to Fla.

There's a small loss of efficiency through moving further north, but not much. The Russians can do it from much further North, so why can't the USA?