The U.S. Supreme Court ruled Monday that state governments should be allowed to legalize sports gambling.

It reverses a 1992 ruling prohibiting most states from sponsoring betting related to sports. 

Only Nevada, Montana, Delaware, and Oregon were exempt. 

The Supreme Court today saying that act violated constitutional principles of states' rights. 

"It's a big win for states rights. No state is required to allow it, today's ruling doesn't answer the question one way or another but it leaves the question to the states," ABC News Supreme Court Analyst Kate Shaw said.

The American Gaming Association reports that Americans wager about 150 billion dollars on sports each year illegally.