One of the absolute worst facets of American political debate is the hagiography of the founding fathers and their constitution. For instance, those idiot teabaggers, crying about how they want their constitution back and how the country should be like what the founders intended. Why? It's the worst, most intellectually vacant argument for or against policy. So much of the constitution is no longer relevant today, but politicians and other Americans still resist changing it because it's "what the founders wanted." It's maddening.
It is completely legal to change the Constitution, it's called an "Amendment".
