John Hinderaker of Power Line posts some interesting background on Obama:

it appears clear that as of 1996, the New Party and its parent organization the Democratic Socialists of America considered Barack Obama to be their guy--one of a handful of avowed socialists running for office at any level in the United States. It strikes me that Obama has some explaining to do.

They have screen captures showing both groups considered Obama as their candidate when he ran for State Senate in Illinois.