INSIDE THE GLITZY OFFICES of the Poker Players Alliance (PPA) in Washington D.C., the furniture looks impressive, but the employees do not. Staff saunter about in Bermuda shorts and flip-flops. The atmosphere is one of easily gained affluence. But don't be fooled by appearances. This is a dynamic organization that wields impressive financial and political clout. The PPA is a leading force in the struggle to legalize and regulate Internet gambling in the United States--a fight it seems to be winning.