The complaint filed in Washington state related to the internet gambling ban is available here. I'm a little unclear on the facts, but the basic point in the complaint seems to be that Washington has legal gambling, including poker, and legal internet gambling, such as on horse-racing, but internet poker is banned. I have not looked at the actual statute to confirm whether that is the right interpretation of the law, however. There are a couple interesting bits of note in the complaint.
First, one of the claims reads almost like one of Antigua's WTO claims:
The IGB violates the U.S. CONST. art. I, §8, cl.3, The Commerce Clause, because it is a protectionist measure designed to discriminate against otherwise legal out-of-state businesses and in favor of in-state businesses. Gambling, internet gambling, and poker are all legal in Washington. Therefore, the obvious purpose of the IGB as it applies to internet poker is to force internet poker players to patronize in-state brick-and-mortar casinos rather than internet poker rooms, which are legal where domiciled and not illegal under federal law, or to switch their internet gambling from poker to horse racing. Such a discriminatory law is virtually per se invalid as a violation of the Commerce Clause. Granholm v. Heald, 544 U.S. 460, 467 (2005)
And there was also this: "a scheme that allows some internet gambling but bars others for protectionist reasons violates federal obligations under the General Agreement on Trade & Tariffs (“GATT Treaty”) as administered by the World Trade Organization." He meant the GATS, of course, but nonetheless it was nice to see a brief reference to the WTO.