Here is an interesting thought:
My friend says that as American politicians are corrupt they can all be hung, shot in the head, or drawn and quartered. And this is legal by common law as they are traitors.
But if this is the case why hasn't it been done already?
Remember that is wasn't technically 'legal' for the 13 colonies to engage in revolutionary war against Great Britain, it was instead necessary.
But to answer your question:
Yes, that is perfectly legal by common law.