uhhhmmm...
I'm kinda bemused here; other space programs, notably China, Russia, and the EU are more proactive than the US...
If its about money, how come the Chinese are still blocked from the 'International' Space Station? (We won't even let the Russians use the American toilet!:])
The Bush Space Plan ? It was fundie funding cuts and for PR's benefit- a return to Spam in a Can.
The main thing that NASA has shown us is that our own Solar System is far more hostile than we thought even 50 years ago (Martian canals, Venusian jungles, etc.)
Even if we discover Earth2, it'll be far more practical to terraform Antarctica or the Gobi- you can catch a bus home from the Gobi- than to ever transport our millions of excess humans offplanet. Migration is not an option, even if we had StarTrek level technology.
