@Brandon9000,
Let's talk about Columbus. First, Columbus wanted to use existing and well tested technology. While three ships plus provisions are not cheap, they hardly break the bank for a country with the maritime traditions of 15th century Spain and personnel to staff those ships were easy to come by. The risk was similar to a naval engagement or a medium sized merchant run. The US risks more in terms of equipment and people in Iraq every day. Second, the government was not resp0nsible to the people of Spain. Even if Isabella had fully funded Columbus out of the public coffers, the people wouldn't have known. She faced no serious accountability. Third, Columbus presented a significant promise of profit. The idea of breaking the land route stranglehold on Asia to Europe trade was a clear, well defined benefit versus a small risk for Spain.
Compare that to our current situation and the challenges become obvious. If you could get into a plane and fly to the moon to explore, this would be a no brainer, but you can't. You have to build new, very complex spaceships with very little that can even be reused. Western governments are completely responsible to taxpayers who might look upon added taxes for space flight as government waste. Finally, there is no clear payoff, no well defined benefit, no timeline for when the profits will start rolling in. Space travel would probably be a money black hole for at least twenty years, probably more like fifty years. No politician, board member, entrepreneur today should have any expectation of seeing a penny from the space program in his working lifetime. The US Congress cannot even agree to form a panel to discuss deficit reduction so I doubt we could expect agreement to fund programs with no hope of bringing home the bacon in time for the election.