Silly you. You should know that there is no such thing as an 'extreme' left wing.
The extremist left wing were those parties in Floriduh that cost Al Gore Junior some votes (Socialist Party, Worker’s Party, Worker’s World Party, Socialist Worker’s Party... even WITHOUT the International Reds’ Green Party, those were sufficient votes to put Lil’ Al over the top).
Ideologically the DNC may be aligned with them but they siphon off votes.