When should Congress get involved with pro sports, Part II?

Back in June, Mike reported on the letter from U.S. Congressman Steve Cohen urging NBA Commissioner and NBAPA Executive Director Billy Hunter to eliminate the league's age limit. I responded by wondering under what circumstances Congress should become involved with issues relating to governance and operations of sports and leagues. Yesterday, Mike reported that Cohen has sent another letter on the subject, this one to NBA President Joel Litvin.

So I am going to be repeat my question today: When is it acceptable or appropriate for Congress (or individual members of Congress) to become involved with issues relating to governance and operations of sports and leagues? Congress was roundly criticized (and I joined in) for the steroids hearings. And Orrin Hatch has been the target of jokes because of his call for hearings about the BCS, after Utah was kept out of the BCS. All such actions are widely met with cries of "worry about the American people, not about college football." On the other hand, the response to Cohen's letters has been positive, at least around here (unless it is only because Rep. Cohen cited Mike's article). And, as I wrote yesterday, the alleged parade of horribles from a bad ruling in American Needle could be undone by a Congress willing to step-in to protect fans and consumers.

So where is the line between Congress stepping into a matter of legitimate federal concern and "don't they have bigger things to worry about"? Is it when members of the public are genuinely being injured, as by the age limit (although the number is incredibly small) or by a Court decision that gave the leagues too much power, while such harm (beyond psychic disappointment) is missing as to the BCS? Is it a difference between internal league matters and those touching on people outside the league? Is it the difference between acting towards the undefined "integrity of the game" (e.g., steroids) as opposed to dealing with the broader business of sports (where sports are not much different than other entities regulated by federal law)? Of course, federal law does speak to things such as gambling, which is all about the integrity of the game.

So is there any metric to guide the actions of legislators?