I take it you are referring to the Congressional Charter bestowed on BSA in 1916. From what little reading I have done on CC's, they appear to function as a fig leaf of Congressional approval. It did not include Congressional oversight. The U.S. House Judiciary Committee decided not to consider applications for further charters in 1992, though several were still granted thereafter.
We are in agreement that BSA National and local councils wanted free stuff from the Feds, e.g., access to camping on federal properties and in decades past free travel on military aircraft. Local councils relied on the public school systems to permit passive recruiting from the student bodies, use schools as the meeting locations for scouting units, and even charter scouting units - especially Cub packs. Progressive education administrators in the public school systems pretty well put the kybosh on scouting in schools since ~ 2000. It remains to be seen whether scouting will recover in public education again.
The real shocking sea change was within corporate America's boardrooms. BSA National and local councils depend heavily upon corporate welfare tribute. The Human Rights Campaign, founded in 1980, worked its way into corporate boardrooms and nearly single-handedly changed U.S. corporate culture with respect to homosexuality. The driving force behind the 2013 BSA National Council meeting which voted to accept open homosexual youths as members was an internal coup of the volunteer BSA National Executive Committee, i.e., < 70 officers who pushed for the change.