Interesting note is that the Equal Rights Amendment never got all the votes it needed to be passed, but there are only 3 states who have not signed it yet... and it has never been rescinded.
So, at any point, those three states could ratify the ERA and it would become a Constitutional Amendment.
I've seen some scholars talking about IF that could happen, and what would happen if it did... but there simply isn't an expiration date on Constitutional Amendments. So ... it could happen.
(But Democrats would have to Do Something, and you know that's out of the question.)