Empty Hands
Senior Master
What does the term "Do the right thing," mean to an atheist? When I get a satisfactory answer to that question, I can say whether or not I would vote for any given atheist who runs for public office.
What does it mean to a theist? You aren't likely to get a coherent answer that covers all theists either. After all, the answer seems to range from "feed the hungry and heal the sick and glorify the Lord" to "kill the unbeliever" or "have sex with underage girls." I think you will find that the average atheist answers much like the average theist - don't hurt others except in defense, tell the truth, help the needy, etc. One can make recourse to a variety of supernatural-free ethical and moral philsophical systems to justify these answers, but most people don't seem to need that, atheist and theist alike.
Demanding some sort of coherent system of morality that covers all atheists is simple bigotry when you don't demand it of theists. Theists have shown that believing in the supernatural can still lead you to do morally terrible things.