A written constitution is an albatross around the neck of a nation. It was written in for a different age and for a unique set of circumstances and has no place in a modern, supposedly progressive society.
Wrong, wrong, wrong, wrong, wrong!
Guns in the hands of the militia (which means "all the able-bodied citizens") protect against tyranny by one, or a few.
A written constitution protects against tyranny by the majority, a/k/a "too much democracy."
Neither of them work perfectly, but they're what we got.