A single shuttle load, 25 tons, of He-3 brought back from the Moon would supply all of the energy needs of the USA for a year.
Rocket scientists agree that we have about reached the limit of our ability to travel in space using chemical rockets. To achieve anything near the speed of light we will need a new energy source and a new propellant. Nuclear fission is not an option.
We need the kind of leadership exemplified by President Kennedy to just do it! But we must do it as good stewards, aggressively exerting control over the moon. We can best do this by going there.
There is more energy locked up in sources around the solar system than we could ever reasonably expect to need, the problem would be transporting them back to earth and using them in a cost efficient manner.