" I'm a bit wary about a government determining what is an ethical norm. A broad or general clause would remain the same in words but the meaning would change over the years, wouldn't it?"
I get what you're saying but: right is right and wrong is wrong. Lying, deception and cheating are wrong, always were and always will be.
Why would a Clause stating as much ever change?
Right and wrong change, don't they? Locking up Japanese Americans would be unthinkable today. I imagine there has been a lot of lying, cheating, and deception over the years. We just don't know about a lot of them. Lying? Deception? There wouldn't be anyone electable.
I would expect the same condition placed on congress congress. Their ethics committee doesn't seem to be working out.