So who is the Government here in America?
Americans and they represent their power as Grand Jurist and Petite Jurist by deciding the facts of the case and the law of the case. That is right We The People are the forth arm of power and the government.

Source : @commonlaw

Thomas Jefferson said: "I know no safe depository of the ultimate powers of the society but the people themselves; and if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education.

The Grand Jury Belongs to The People–Antonin Scalia (1992)

As proof: Supreme Court UNITED STATES, Petitioner v. John H. WILLIAMS, Jr.
https://www.law.cornell.edu/supremecourt/text/504/36