I strongly disagree. The writers of our Constitution clearly stated that it is only suitable for a morally upright people or it otherwise will NOT work.
And I agree. The morally abject use our laws (yes, our Constitutional laws) against us, to their advantage.
They now number just over 50% and are the majority in power.
If people are immoral enough to ignore the law than no law will restrain them regardless of the law or the form of government. It is not unique to our republic.
If, as people here have claimed, our constitutional republic is the form of government inspired by word of God I would expect more Christians to understand the basic principles of constitution but an unfortunate amount don't. In fact I know people very knowledgeable concerning the bible that really don't grasp why we need a separation between church and state.