I've heard this same brainvomit over and over again, from people whom I had previously considered smart enough to tie their own shoes, come in out of the rain, and operate a toilet without sustaining severe personal injury.
"The Constitution is a failure!! It didn't protect us from the shit that's befallen us!! It's useless!! Waaah!!"
Well, of course it didn't protect us, you bucketheads. The Constitution is a piece of paper with some ink on it. It just hangs out there under glass in the Smithsonian, not doing a whole lot of anything. Counting on the Constitution itself to somehow 'protect' you is like trusting that your psycho ex will stop slashing your tires and setting fire to your pets because you got a Magical Restraining Order. Or that a disciple of evil bent on the massacre of innocent human beings will be deterred by a sign declaring "GUN FREE ZONE."
The Constitution is simply a list of laws. And as any thug will tell you(or demonstrate if you let your guard down), without enforcement, laws mean nothing.
The Constitution didn't fail US, you simpletons...WE failed IT.