You wanna talk about the Constitution? Here’s the clause regarding the States role in regulating Federal elections:
Article I, Section 4, Clause 1:
The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Places of choosing Senators.
So it’s clear that according to the Constitution, the power to determine the “Manner of holding elections” (referring to Federal elections) lies solely with the State legislatures. Not the Governors or Secretaries of State or State Supreme Court. Unfortunately many states with Democratic leadership but Republican legislatures decided to sidestep this clause by using their (Democratic) State Courts to amend the laws to favor their party. (Mail-in ballots, no signature verification, and extended deadlines tend to favor the Democratic party.)
These are the same people who then lecture us on Trump violating the Constitution.