What legitimacy does the U.S. government even have anymore

The Constitution of the United States of America, the Bill of Rights, and the Supreme Court.

Why do we keep listening to them?

Democracy, loyalty, nationalism, trillions of dollars, global power, the Army, Navy, Marines, Air Force, National Guard, FBI, CIA, local and federal police, the largest surveillance network in the world, thousands of prisons, and a million other reasons.