The NYT wrote an article saying they believe believe the attacks are coming from Lehane
All's Fair? Clark Rivals Irked by an Aide's Tactics
http://www.freerepublic.com/focus/news/1058945/posts The documents — those nasty tidbits that campaigns euphemistically call "opposition research" — are flying in the scrappy final days of the Democratic contests here and in Iowa. At the center of the maelstrom, Democrats say, is a 36-year-old aide to Gen. Wesley K. Clark, a frenetic, colorful and, some contend, devious communications strategist named Chris Lehane.