Andy Stern didn't say that labor -- i.e., all American workers -- would be "better off" economically if John Kerry lost, but he probably does think that if Kerry wins -- especially if Kerry wins too easily, with no one in and out of the Democratic Party making any demands on him from the left -- the bargaining position of organized labor and other liberal interest groups vis-a-vis the Democratic Party elite would erode further, because an easy Kerry victory would strengthen the hands of top-dog Democrats who argue that moving the party to the right rather than to the left is the road to victory.
Stern also probably believes that it takes not just internal forces but also external pressures to move the Democratic Party to the left, but external pressures are precisely what is lacking today, made to disappear in part by the culture of Anybody But Bush and Nader.
Yoshie