That's an operational problem, not a design problem. I can design a perfectly functional car, with a whole set of capabilities. But that doesn't prevent someone from getting behind the wheel, starting her up, and mowing down a sidewalk full of people. Is the car broken? No. The accident was a result of driver error.
So it is with the USA. The system is fine. All the parts still work. The people running the system, and that means all of us, have less than a perfect record. I don't think anyone expected perfection. How bad is our performance? It's not an easy thing to quantify. The best thing you can say, and it's no small thing, is that we have preserved our system so well that we still retain the power to govern ourselves. In fact, we have done a lot better than a lot of folks at the time thought we would.
Words have meaning, A=A, you say. You must not know any lawyers. Words have meanings. Just look at the 1st Congress. You had the key framers hotly debating the most fundamental phrases in the Constitution. Madison fought Hamilton over the National Bank, only to authorize one himself later on when he was President. You had Adams, a profound patriot and republican, signing the Sedition Acts. Clearly, if Washington, Madison, and Hamilton could not agree on the meaning of the words, then saying A=A doesn't say very much that is useful.
We can't expect words on their own to save the day. What's amazing is how well and how much of the words have held up, while the rest of the world has gone through tumultuous upheavals--fascism, communism, socialism, etc. As I say, the system, that is, the fundamental laws which describe our system, are in good working order. The people can always do a better job of running it.