Trump had a good reason for firing Comey. While the White House has offered several reasons for the firing, The biggest one seems to be that Comey knew that Trump was innocent of dealing with the Russians but refused to say so publicly, despite the damage his silence was causing the president. Among other things, the (non-existent) investigation was given by Democrats as a reason to hold up Trump's Supreme Court nominee. Comey was quite free in confirming the investigation of Hillary Clinton's email server despite the damage that did to her campaign but he was unwilling to be as flexible for a sitting president.
Trump was never under investigation. This is a big one. A major justification for opposing Trump was that he is Putin's puppet (or worse according to a foul rant by Stephen Colbert). Comey's testimony showed that Trump was never suspected of colluding with Russia. Further, Trump was all in favor of investigating any of his "satellites" who had cooperated improperly with the Russians. That ends the hope of somehow nullifying the election.
Trump only asked Comey to go easy on former National Security Advisor Flynn. Flynn was only being investigated because Trump appointed him. This comes across to me as Trump suggesting that being forced to resign was enough punishment but that he left it up to Comey. Comey testified that he took it as an order which he chose to ignore. It must not have been much of an order since he did not report Trump following up on the request. I suspect that when you choose to ignore a direct order by Trump, he does not forget about it and let the matter drop. It would be impossible to impeach Trump on obstruction of justice charges based on this (which hasn't stopped the left from screaching).
Trump was correct in mistrusting Comey. Comey didn't trust Trump and acted accordingly.
Yesterday former FBI Director Comey testified before Congress. Many on the Left had been hoping that this would be a knock-out for Trump's presidency or at least the beginning of the end. It was not. Here are the big take-away:Trump asked for loyalty. As soon as the election was called in Trump's favor, Obama hold-overs vowed to resist his presidency in any way possible. While there are several interpretations of what Trump meant when he asked Comey for loyalty, the most likely is that Trump was asking Comey to do his job impartially instead of undercutting Trump from undercover. Comey offered his honesty which Trump accepted. This shows that Trump way manly asking Comey to do his job.
The Obama Justice Department did try to obstruct the investigation of HRC's email server. Among other things, Comey was instructed to call it a "matter" rather than an "investigation".Comey is pretty sleezy. He took a lot on himself. He decided to make a public announcement about the email server and make it in such a way that no charges would be filed despite that being outside of the FBI's authority. He claims to have decided to ignore an order from the President on an investigation. He leaked his memos to the press in the hope of starting an independent investigation but he never gave a good cause for investigating anything.