At what point is a revolution justified? (what is the moral criteria)

Response to comment [from an atheist]:  "When does 'No' have meaning?..."

This is why pitchforks were invented.

Response to comment [from a Christian]: "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, — That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness."

Christians should occupy positions in government (Gen. 42:6), pay taxes (Matt. 22:18–21), pray (1 Tim. 2:1–3), and obey (Rom. 13:1–7) but obey God first (Acts 5:29).  Thomas Nelson Publishers. (1995). Nelson's quick reference topical Bible index. Nelson's Quick reference (262). Nashville, Tenn.: Thomas Nelson Publishers.

"Rebellion against tyrants is obedience to God." Benjamin Franklin

Response to comment [from an atheist]: "No, it's why the gun was invented. Preferably high caliber, fully automatic and belt-fed.  Pitchfork are for farming."

That's what I meant, farming. :  My point is, the Tea Party movement is getting noticed.  People have every right to peacefully protest.  They'd like to throw the bums out at this point.  Unfortunately, there are many bums right behind them.

"I don't know about you, but I live in a country that has freedom of religion."

You have that right because Christians founded this country.  You are an atheist (against God).  Others here identify themselves as agnostic (against knowledge).  Fine.  You have been given a free country by the blood, sweat and tears of others.  I'm sure they would have preferred to die for the godly; but, so be it.

"[]I]t should not matter what the religion is of those occupying government."

Christians are fit to lead.  They know God's heart.  They ensure that his will is sought for our nation.  We see what happens when the godless take over (Prov 29:2).  

"They should obey the wills and needs of the people first."

We should seek God's will (Ex 23:2).  When we don't, we head downward--which is where we are now. 

At what point is a revolution justified? (what is the moral criteria)