If there are going to be people out there making war on other people, don't you think it's a good idea for some of those people to at least follow a code of ethics? Not 'honor' but something you can pin down and be sure of, something with the same rules for everybody.
I don't have many litmus tests, but this is one: Any candidate who doesn't understand that we need to balance the budget should not be president of the United States.

