Needless to say, no one sticks to this principle. For example consider Jon Chait on Clinton defenders
In the eyes of their enemies, the Clintons are criminals on a world-historic scale; in the eyes of their supporters, innocent victims of a massive smear campaign. The reality is that their venality is rather ordinary. There’s a reason the term politician is synonymous with lying, calculation, and ambition — these are common qualities for politicians. The Clintons are common politicians, motivated in general by a desire to implement policy changes they think will make the world a better place, but not immune to trimming and getting rich in the process. None of their behavior is disqualifying, given the number of elected officials, presidents included, who have done the same. Neither does it justify it.
Note that Chait doesn't name any Clinton supporters who think the Clintons are 0% guilty of any unethical conduct. Contradicting both the (un-named and un-quoted) enemies and the (un-named and un-quoted) supporters Chait wrote that the Clintons are " not immune to trimming and getting rich in the process." That should teach all those people who think that the Clintons are immmune to "getting rich in the process." These people aren't named, because Chait hasn't found any (personally I am confident that there are at least two people in the world who think the Clintons aren't rich -- those people are either totally ignorant or so rich that they think only billionaires are rich). I think the number of people who think that the Clintons are immune to trimming is probably greater than the numbe who think they haven't become rich. I'm sure there are people who see no trimming in having Ricky Ray Rector killed and then applauding Lionel Jospin when he said it is disgraceful that the death penalty hasn't been eliminated. I'm sure there are more people who don't know that Bill Clinton did both those things. But I think only a tiny fraction of Clinton supporters suspect them of an inability to trim.
Chait has set up an imaginary Clinton supporter straw person. Notably, he didn't express an opinion one way or another on the question of whether both Clintons are more nearly "immune to trimming and getting rich in the process" than 90% of other politicians. He didn't address that question anywhere in the essay. For example he didn't assert that Bernie Sanders has higher ethical standards than Clinton.
Yet in his concluding sentence he wrote "her [Clinton's] lax approach to rule-following and ethical conflicts." This follows no effort at all to demonstrate that her approach is lax given the ordinary English meaning which is "laxer than is usual" not "laxer than Kant's ideal citizen of a realm of ends".
Throughout Chait shifts back and forth from discussion of perceptions to discussion of reality. I would have no problem with an essay on how Bill Clinton's wife must be above suspicion, but the words "her lax approach" would not appear in that essay.
I have three more complaints. Throughout Chait does not consider the fact that Bill and Hillary Clinton are two different people. I am fairly confident that an alien who generally understood English but hadn't figured out how the singular and the plural are distinguished would guess after reading the essay that "the Clintons" is a single being.
I object to Chait's abuse of polling data. To argue that Clinton has a problem with young people he looked at a single poll, the Pew poll which showed Clinton winning by an anomalously low margin.
The most recent Pew Survey finds Clinton winning the under-30 vote by a mere 11 percentage points, 38 percent to 27 percent, less than half the margin Barack Obama carried four years ago.
I think there should be a rule for commentators that only polling averages with explicit and defensible rules for inclusion and weighting should be discussed. update: I should have guessed that Nate Silver has calculated the average. In post convention polls, Clinton-Trump averages 21% or approximately twice Pew's 11% and similar to Obama-Romney. Chait cherry picked the Pew poll.
Also he compared Clinton-Trump to Obama - Romney without making the source of the Obama-Romney datum clear. The participle "carried" to me implies that he is discussing an exit poll. It is not legitimate to Compare an August poll to an exit poll. He looks at the difference in support not the ratio of support. This is important, because he is discussing a poll in which only 65% of the subset of respondents said they were voting for Clinton or Trump. His point would not have been supported by the equally valid calculation (Clinton - Trump)/0.65 vs (Obama -Romney)/(98 or 99% or whatever). This is bogus.
Then (and worse) Chait equates " the Democratic electorate as a whole. " "Voters who supported Sanders in the primary, but who have not embraced Clinton" and those who reflect "the heart of Sanders’s appeal ". here
But the professional left does not reflect the Democratic electorate as a whole. Voters who supported Sanders in the primary, but who have not embraced Clinton, are actually less liberal on the whole than Clinton’s supporters. That is because the heart of Sanders’s appeal was to good-government voters who embraced his image as an authentic practitioner of earnest, uncorrupted politics.
This is nonsense. The only data he mentions are the views of "Voters who supported Sanders in the primary, but who have not embraced Clinton" a small minority of a minority of the Democratic electorate. These people are a minority of Sanders supporters. Their views can't teach us what was the heart of his appeal. The analysis is nonsense.
Finally Chait argues that The Clinton Foundation does good work fighting AIDS and poverty, but has to be eliminated to eliminate the appearance of conflict of interest. His arguments logically imply that some people whose lives could be saved will just have to die of AIDS or malnutrition for the greater good. I think this is his view -- the work of the Clinton Foundation isn't important. My guess is that, if pressed, he would argue that the same money would be given even if the Clinton name were not used. This is inconsisent with the ordinary English meaning of the word "leverage" in "The purpose of the Clinton Foundation is to leverage Clinton fame into charitable donations." Now Chait is bold and might just argue that the lives which would be saved by the Clinton Foundation will have to be sacrificed for the greater good. The stakes are high and this is actually arguable. But Chait didn't bother to argue this.