Kennedy: Let's go to the Moon. We go to the Moon.
Nixon: Apollo canceled. Shuttle born.
Reagan: Space Station Freedom. The Ride Report proposes a lunar base by 2010.
Bush Sr: Space Exploration Initiative, or $500 billion for a lunar base by 2010 or 2020. Rejected.
Clinton: Space Station Freedom morphs into ISS.
Bush Jr: Constellation program and humans on the Moon by 2020.
Obama: Constellation canceled, SLS born. Moon by 2020. Or maybe an asteroid by 2025. Or maybe Mars (with friends). Or maybe somewhere else entirely...*