Allow me to point out that although locus standi has ancient origins and arguably may or may not be to some limited extent an implied restriction on the powers granted by the Constitution to the Supreme Court, it was not used by the Supreme Court of the United States until 1922; and locus standi is arguably unconstitutional to the extent it is employed to subvert the Constitutional imperative
“Section. 4. The United States shall guarantee to every State in this Union a Republican Form of Government....”
Note how this imperative has been acknowledged and addressed to various limited extents by similar legal systems.
Standing (law)
From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Standing_%28law%29
Standing or (locus standi)
Arguably, the 1922 implementation of Standing is another part of the overall effort to wrest control of Federal, State, and local government away from the citizens and place that control into the hands of a very small, corrupt, and self appointed elite group.
SCOTUS avoids peeking on a separation of powers doctrine. It doesn’t deny standing to plaintiff.