Re: Ranger etc. missions
I'm pretty sure Kennedy didn't "believe" in space exploration. The simple fact is that the Soviets had a new shiny-shiny and the Americans had nothing equivalent. Putting aside the fact that the reason the Soviets had the shiny-shiny was because their nuclear warheads weren't up the US specs, they had demonstrated a clear technological superiority in the new field of spaceflight. And that wouldn't do.
Hence Kennedy picking a target which was so far out it made previous accomplishments fairly irrelevant.