You got me. Mea Culpa...The only thought on my mind at the time of reading, assuming that the constitutional amendment had already passed through congress, which indeed does require a super-majority, is that it needed to be ratified by the states and that in order to do that, it also required a (more than) super-majority. Don’t knwo why I identified 2/3 vice 3/4 except that I must be getting mushy in the brain. As indicated by another poster, I am an old fart!
You're in good company Chief.