The first is that complaining about someone and calling for that person to be fired are two totally different things. Because when you don't grasp that, you fall into a sink hole where you fail to realize a harsh reality: that Trump and his supporters are unable to point to ONE Democratic leader who actually ever called for James Comey to be actually FIRED.
Much as Democratic leaders had their problems with Comey during the campaign, they also clearly understood that an FBI Director is supposed to be an independent agent outside of politics -- free to be criticized to the ends of the earth, but with a 10-year term that is intended to keep the job from being politicized. A position where firing is the very last option, indeed something that only has ever occurred once. That was when then-FBI Director William Sessions (not related to the current Attorney General) was fired by President Bill Clinton -- which was for issues related to the FBI director breaking laws and having ethics violations. Galaxies different from "He wasn't doing a good job," as Trump spat out.
(By way of reminder, an internal report had charged that William Sessions had evaded paying taxes and refused to cooperate with law enforcement that was looking into problems with his home mortgage loan. It's also worth pointing out that this initial study was done by the Justice Department's during the George H.W. Bush administration. Only then was the matter passed on to Clinton who had his own Attorney General Janet Reno do a follow-up study. Checking your scorecard, then, this means the Sessions firing -- the only previous time an FBI director has been fired -- went through two presidents.)
So, as much as Team Trump wants to say that Democratic leaders were all calling for James Comey to be fired -- the pesky, inconvenient reality is that not only were "all" Democratic leaders not doing so...none of them were. Slate magazine has an article about this, as well. You can read it here.
Which leads to the second major discrepancy from the Trump folks that is critical to keep in mind. And that's that it's one thing to fire an FBI director, even for cause (or not), but it's another matter entirely to fire him when he is in the midst of leading an investigation against you. Even if Democratic leaders had all called for President Obama to fire Comey -- which none of them did -- Mr. Obama wasn't being investigated by the FBI. It's a massive distinction, and one with not only substantive meaning, but perhaps legal meaning, as well, if it turns out to be a matter of impeding an FBI investigation and abuse of power.
(And all this, of course, doesn't even include how Trump himself is the man who praised Director Comey as doing a great job, loved him for reopening HRC inquiry and then fired him. So, tossing around charges of hypocrisy -- even if there was any, which there isn't -- seems an incredibly risky business as a starting point. All the more so when your starting point is that problematic "Impeding an FBI investigation.")
By the way, the Washington Post has a tremendous and meticulously-documented (with 30 sources) front page headline article about the relationship between Trump and Comey which lead to the firing. It's titled, "Inside Trump's Anger and Impatience -- and His Sudden Decision to Fire Comey." You can read the whole thing here.
It's compelling reading. It also includes an important revelation that Deputy Attorney General Rod Rosenstein was apparently so angry at how the story was played by the White House, which was suggesting that the decision was prompted by him, that he threatened to resign.
But to me, the most important passage in the long run concerns how the FBI reacted to the firing --
"Many [FBI] employees said they were furious about the firing, saying the circumstances of his dismissal did more damage to the FBI’s independence than anything Comey did in his three-plus years in the job.
"One intelligence official who works on Russian espionage matters said they were more determined than ever to pursue such cases. Another said Comey’s firing and the subsequent comments from the White House are attacks that won’t soon be forgotten. Trump had 'essentially declared war on a lot of people at the FBI,” one official said. “I think there will be a concerted effort to respond over time in kind.'”
Trump has basically declared war on the FBI and CIA, as well as the National Intelligence agency, demeaning them all -- and now firing the FBI's director and threatening its independence. Let me just state a purely personal opinion that I think it's probably not a good idea to make an enemy of the FBI, CIA and National Intelligence agency.
I could be wrong, but that's just me...