I think the phrase is nonsense, and applying it to the difficulty of amending it even worse.
When was the last substantial amendment to the constitution, meaning a true change to the social fabric? Lowering the voting age to 18 in 1971? A mere bump. Eliminating the poll tax in 1964? A significant statement, but hasn’t stopped states from finding other ways to limit voting. Prohibition or its end? I’d put it back at Women’s Suffrage in 1920.
How much has the country changed in the past century? Enormously. The country changes whether or not the Constitution does. Laws, the judiciary, the presidency, the economy, the demographics, the social climate, technology, foreign events, everything changes constantly. What realistic amendments to the Constitution would have more than symbolic effect on those?
The Constitution is a framework. With a few major exceptions, we’ve gone from a set of loosely affiliated farm-based colonies to the world’s technological and economic superpower under exactly the same framework since the Bill of Rights was passed. Maybe even before, since the framers thought those rights to be too obvious to need writing down.
In that time, the U.S, went from 13 to 50 states, from 4 to 330 million people, from a federal system that barely existed to one of hundreds of thousands of pages of laws. We’ve coped with almost every conceivable catastrophe. To be sure, we’ve tossed the Constitution aside every time we’re gotten into a major war, but somehow pledged our troth to it immediately afterward.
The Constitution is a mythology, not a barrier or a bulwark. It’s barely a scaffolding. Like our money, it has exactly as much value as collective opinion gives it. We can do anything we want under it and not do everything we want if the right people object. It’s always been thus, since the first day.
I’m not being optimistic. I’m never optimistic. I do try to be realistic, and my reality is that using the Constitution as the reason for not getting your way is simply an excuse to deny reality.