Carter essentially killed space exploration in the USA for a good while. Even when Carl Sagan went to him in person to ask him to support planetary probe missions, he didn't do it.
And Carter is supposed to have been one of the smarter Presidents. Sagan was able to convince Senator Proxmire to support SETI, and Proxmire clearly had a weak grasp on the science.

And ironically Carter is the one who got to put a message on the Voyager Interstellar Record.

http://en.wikipedia.org/wiki/Jimmy_Carter

http://home.att.net/~jrhsc/jimmy.html

Of course this happened for the same reason that Nixon got to get his name on all the Apollo Lunar Lander dedication plaques - because he happened to be the President at the time, not because he was a space supporter.