Nearly a day doesn't go by that a Democratic politician or strategist doesn't remind Americans that Trump may have illegitimately been elected because of collusion with the Russians. This is despite the fact that ongoing concurrent investigations in the House, Senate, and the FBI have not produced any evidence to support it
So, it was no wonder then, that when Trump fired FBI Director Comey, the Democrats automatically smelled a rat. Immediately, Senate Minority Leader Chuck Schumer demanded a special prosecutor under the assumption that Comey's dismissal was a direct result of his investigation of Russian interference in the election. Therefore, the Russia/Trump controversy continues to have legs.
However, there is an obvious flaw in that thinking. Comey being fired does not stop the Russia investigation. And unless Comey was extremely hands on and had nothing else to do, there is most likely some lead investigator at the FBI who is actually in charge of thet investigation. That's the reality.
My problem with the Comey firing is why it took so long. Trump should have let him go early into his presidency because of the way he -- not the Russians -- interfered in the election regarding Hillary's email server. In addition, the way the firing was handled was a violation of every code of conduct for any executive. You just don't fire someone by letter unless that person simply isn't available. The proper thing to do is to have a face-to-face meeting in which the person being released receives a full understanding as to why he/she is being let go. That was not the case, and it clearly shows an insensitivity on Trump's part that I find reprehensible.
Pence Calls Comey Firing 'Right Decision' as Democrats Pounce: http://www.nbcnews.com/politics/white-house/democrats-charge-comey-firing-nixonian-demand-special-prosecutor-n757121
Chuck Schumer calls for special prosecutor for Russia probe: https://www.bostonglobe.com/news/politics/2017/05/10/trump-takes-twitter-defend-comey-firing-decision/5ozYTKF0klYhBhmRiDkNjO/story.html
Comey Firing Was Inevitable--Surprise Is It Took So Long: https://www.usatoday.com/story/opinion/2017/05/09/james-comey-fired-donald-trump-fbi-director-column/101488186/