One thing that I have learned, is that when a person tries to defend the indefensible, they always bring up something from the past. Whatever Clinton, Reno, or others did during prior administrations has absolutely no bearing on our current President's behavior.
Good grief, you managed to package a lot of stupid into two sentences. No offense intended obviously. In the first place, that you think a superior firing a subordinate is "indefensible" is a tell. Because that happens every day. So absent bias, it's not indefensible, it's mundane. Your characterization of an every day occurrence as "indefensible" in the absence of nefarious motive - and those of your political persuasion have been calling for Comey's ouster for nearly a year, because people of your political persuasion have until recently blamed Comey for the repulsive Hillary Clinton's election woes - belies your bias; as opposed to my reaction, which is a shit-happens shrug. That some guy fired some other guy isn't news, absent other facts, none of which exist.
More commonly when a person tried to defend the indefensible they don't cite precedent, they lie and dissemble. People who defend the Holocaust don't cite Middle Age pogrom as justification, they claim it never happened or that the victims deserved it. People who defend slavery in the US under Millard Fillmore don't bring up the policies of Zachary Taylor. They don't say slavery should be legal because slavery was legal in Egypt. They don't say women should be denied the vote today because women were denied the vote in Macedonia. Quite the opposite: they cite antediluvian and phantasmagorical and absurd theories about genetics or phrenology. So to that extent you're talking nonsense.
And to complete the nonsense: more often when people bring up things from the past it's not to defend the incongruous or indefensible in the present, it's to defend the normalcy of the past. People who think murder is bad cite the ten commandments. People who think all people are deserving of civil rights cite the constitution or natural law. Which past is in fact what the entirety majesty of the law is based upon: that normalcy today is predicated upon what happened prior to what happened today. It's called the common law and it's the basis of civilization and society.
Other than that you make some good points.