Technology is the future. It will create jobs and add some measure of security to a nation. To remain strong this is how any nation, and certainly the U.S., needs to invest in it's future. The bigger debate is if the space program is the best investment. I'm not sure on that but it does carry a higher level of prestige. I've always thought NASA does a very poor job of promoting all the spin off technology that does find it's way to the private sector. That's not to say that this technology would not have been developed eventually. My opinion, and it's only an opinion, is that this is still a good return on investment - even if the return is ten or more years. I've always heard it said that some of the early development in computers and telecommunication was driven by the space program. If that's true it certainly has generated many jobs world-wide. Of course being a scientist I am biased in favor of scientific advancement - even if it's only increasing our understanding.
Chuck