Congress isn't stepping in to protect the small schools. They definitely aren't stepping into protecting the non-public schools. Washington's congressional delegation isn't protecting Gonzaga's rights if it runs counter to UW's interests. Nebraska's legislature isn't looking out for Creighton at Nebraska's expense, Marquette vs Wisconsin, Villanova vs. Penn State, etc.
If the P4 chooses to break away, they'll do it and they'll end up controlling the vast majority of the money. Instead right now they're avoiding the headache by pushing for tournament expansion that will heavily favor them. I wouldn't be shocked if the next salvo is a structure to the units that favors the larger conferences (or potentially the later rounds, where the P4 schools would gain more than the smaller schools who benefit more from the early round upsets).
I disagree with you. Using your Washington example, one of the Senators, Patty Murray is a graduate of Washington St. So, she will be OK with Washington St. being excluded? What about Oregon? Oregon St.'s enrollment is 50% larger than Oregon's. And, in a state like Pennsylvania, you are going to exclude Temple, St. Joe's, Penn, Villanova, Drexel, Bucknell, Duquesne, LaSalle, Lafayette, Lehigh, Robert Morris? Or are New York senators going to help Syracuse over SUNY Buffalo, SUNY Albany, SUNY Binghamton, Niagara, Canisius, LeMoyne, Colgate, Columbia, St. John's, Marist, Siena, St. Bonaventure, Hofstra, SUNY Stony Brook, Wagner, West Point, Fordham, Manhattan, Wagner, Iona,... ? In California, there are 22 basketball schools not in the P4 vs 4 schools in the P4. In Illinois, there are 11 basketball schools not in the P4 and 2 that are in the P4. In SEC country, the non P4 schools overwhelms the number of P4 schools.