Why Did Trump Fire Comey?

The Left is apoplectic now that Donald Trump has fired FBI Director Jim Comey, despite calling for this very thing themselves for most of a year.  Many reasons have surfaced as to why Trump may have taken this action at this time.  Among them:

• Comey's bizarre press conference last summer where he laid out the case against Hillary Clinton's handling of classified information, and then excused her on the basis of "intent", which, of course, is not part of the statute.
• Comey's bizarre intervening in the Loretta Lynch / Bill Clinton tarmac meeting.
• Comey's bizarre letter re-opening the Clinton matter days before the election.  (Which actually hurt her, and helped Trump.)
• Comey's bizarre recent testimony in front of Congress.
• The Left believes Comey was onto Trump's supposed Russia collusion, and therefore had to be eliminated. (Yet, Trump would have to fire the entire FBI to keep that from being made public, since an investigation of that scope would likely involve hundreds.)   

That said, there is another strong case for why Donald Trump fired Jim Comey.  He is a partisan.

Remember Trump's famous tweet about being bugged by Barack Obama?  Right before that tweet, Reince Priebus, WH Chief of Staff, had asked Jim Comey to publicly state what he had already been saying privately, that there was zero evidence of any Russia collusion.  Comey turned him down flatly saying, A) the FBI doesn't get involved in political squabbles, and B) they don't comment about investigations.  Then, right after that, Trump tweeted about his phones being tapped, and what did Comey do?  He immediately, and publicly, came out and said there was no evidence Obama bugged Trump.

Bam! Trump knew instantly he had a partisan FBI director who was applying a double standard.


(UPDATE)
Here's a timeline of the events from 2/24 to 5/8:

2/24 -  Reince Priebus asks James Comey to publicly admit there is no evidence of Russia collusion. Comey turns him down citing it as a political squabble and part of an investigation he cannot comment on.

3/4 - Trump tweets about Barack Obama wiretapping him. 

3/5 - James Comey immediately and publicly denies Obama had Trump wiretapped.  How could he possibly know this within a day, and be so certain that he could state it publicly given that the resources available to a POTUS for surveillance go well beyond the FBI?  And how could he possibly comment on this political squabble while the Russia collusion squabble was off limits?

3/20 - Comey public testimony undercuts Trump's claim of wiretapping.  Apparently, Comey had been calling Trump "crazy" among colleagues for his tweet.

4/4 - It turns out members of the Trump transition were surveilled and improperly unmasked - the equivalent of being wiretapped.

5/8 - Deputy Attorney General Rod Rosenstein's memo makes case against Comey, which Trump uses as his opportunity to fire James Comey.