Multinational corporations have a new ally in their battles with organized labor: unionized workers.

As organized labor loses leverage in a race-to-the-bottom global market, some workers are becoming so disillusioned by what their unions can, or rather can't, do for them that they want out. The disaffected include dozens of machinists at Caterpillar Inc.'s plant in Joliet who crossed the picket line during a strike last summer and are planning unfair labor practices complaints against the union.