I'm sure that most of you know the famous saying, "Power tends to corrupt, and absolute power corrupts absolutely." I'm also pretty sure that a large percent of you who know the saying also know that it was the famous 19th century liberal (we would nowadays call him a classical liberal or a libertarian), Lord Acton, who said it.
What I found striking, when I went and looked for the quote, is the line that comes directly after. In fact, it's so striking that, when it's relevant, I use it in speeches and in interviews. The immediate next line is this: "Great men are almost always bad men."
I cannot accept your canon that we are to judge Pope and King unlike other men, with a favourable presumption that they did no wrong. If there is any presumption it is the other way, against the holders of power, increasing as the power increases. Historic responsibility has to make up for the want of legal responsibility. Power tends to corrupt, and absolute power corrupts absolutely. Great men are almost always bad men, even when they exercise influence and not authority, still more when you superadd the tendency or the certainty of corruption by authority. There is no worse heresy than that the office sanctifies the holder of it.
When I read that, I immediately think of the question Hayek addressed in a chapter of The Road to Serfdom titled "Why the Worst Get on Top." Surely, this moral blank check is one of the reasons. If people think "the office sanctifies the holder"--I think of Sean Hannity of Fox News Channel, for example, who often talks about how he respects the office of the Presidency no matter who is President--then it's easier for the office-holder to get away with bad things. Who is attracted to the Presidency? All other things equal, people who want to get away with bad things.