Pro Tip: Only the People can change the Constitution (generally with the help of Congress)
When a president or candidate claims to be a protector against or progenitor of changes to the Constitution, do not believe them.
The president’s role in repealing the Second Amendment or preventing its repeal is operationally zero. The same is true of adding new amendments – e.g., the ERA.
The process is completely contained in Article V. The tl;dr is: if two thirds of both houses propose an amendment (enough to override a veto, were one even possible, incidentally) and three fourths of the state legislatures or conventions therein approve it, the proposed amendment becomes part of the Constitution. (There’s an alternative way to start the ball rolling, but the 3/4 approval by states always has to happen.)
The chief executive’s only input or output is the ability to shout from the Bully Pulpit. That’s it.
The judicial isn’t involved, either. It’s just us.
So don’t vote based on that crap.