To explain the joke:
The terrorist group Bill Ayers was a part of in the sixties was called the Weather Underground. Obama has ties to Ayers. The linked website is called Weather Underground. there is a town in Japan, apparently called Obama. Thus a link between Obama and Weather Underground.
ha ha ha ha
Big Don, and MACaver, I am older and understood the word play. I am very familar with the weather underground, also known as the underground weathermen. Obama has the last member alive as a friend and nieghbor.