We now have various threads going on about what will happen if Trump refuses to leave after losing the election. Any scenario in which he attempts to stay will likely involve Trump himself, or possibly William Barr, issuing illegal orders.
The question for this thread, then, is this. What are some historical examples of top officials, whether civilian or military, of someone refusing an order on the basis of the order being (in the opinion of the person receiving the order) illegal. Let’s try for examples from the United States, the closer to the present day the better, and the higher the levels involved the better. If no such examples exist, then let’s expand this to other democracies, further in the past, and lower levels of government. Let’s exclude any examples from non-democratic countries, where it’s likely the response will be to “disappear” said person.