Original: He was the Democratic nominee for Vice President in 2004, and was a candidate for the Democratic presidential nomination in 2004 and 2008.
Simplified: He ran for President of the United States twice, in 2004 and 2008, but was defeated by John Kerry and Barack Obama in the Primaries. He was also chosen to be the Democratic candidate for Vice-President in 2004, but was defeated by Dick Cheney.