Entertaining tournament a prelude to a murky future for the NCAA

Connecticut head coach Kevin Ollie answers a question during a news conference for their NCAA Final Four tournament college basketball semifinal game Thursday, April 3, 2014, in Dallas. Connecticut plays Florida on Saturday, April 5, 2014. (AP Photo/David J. Phillip) (The Associated Press)

From left, former Northwestern University football quarterback Kain Colter, Ramogi Huma, founder and President of the National College Players Association and Tim Waters, Political Director of the United Steel Workers, arrive on Capitol Hill in Wednesday, April, 2, 2014. Members of a group seeking to unionize college athletes are looking for allies on Capitol Hill as they brace for an appeal of a ruling that said full scholarship athletes at Northwestern University are employees who have the right to form a union. Former Northwestern quarterback Kain Colter _ the face of a movement to give college athletes the right to unionize _ and Ramogi Huma, the founder and president of the National College Players Association, scheduled meetings Wednesday with lawmakers. (AP Photo/Lauren Victoria Burke) (The Associated Press)

The tournament that began with the lure of a billion-dollar bracket will come to a close at a billion-dollar stadium outside of Dallas.

Big as March Madness and the Final Four have become, they're not big enough to blot out the storm clouds on the horizon. The NCAA has issues looming — among them, the possible unionization of players and a lawsuit challenging the NCAA's ban on paying players.

If the NCAA loses either case, it would threaten almost everything. That includes its most lucrative and intoxicating event: The basketball tournament, which is celebrating best-in-a-generation TV ratings, a record number of overtime games and a staple of big-name programs — Florida, Wisconsin, Connecticut and Kentucky — that made it through hours of entertaining action en route to the Final Four.