My response to the person who said it was a failed experiment?
Well, what would that new and better "something else" be?
Thus far, humankind has tried theocracy - failed; dictatorship - failed; monarchy - failed; pure democracy - failed; communism - failed; socialism - failed; anarchy- failed. In fact the only form of government that has succeeded where all others have failed is a republic. It didn't fail in Rome over 2000 years ago, the Romans traded it in for a dictatorship and it isn't failing in the United States.
Republics never fail, but as Franklin tried to enlighten all its future benefactors - it can only be lost by giving it up and no longer striving to keep it.