This is just my opinion, but the widely expressed view that Trump fired Comey in order to shut down the Russia investigation seems to overstate Comey’s role in an investigation that in his absence still proceeds.
The reports of Trump screaming at television coverage of the investigation, do not suggest that he is in the midst of a carefully crafted cover-up.
Most importantly, having publicly deferred to the judgement of Deputy Attorney General Rod Rosenstein — as did Attorney General Jeff Sessions — Trump has effectively handed a veto to Rosenstein when it comes to the choice of Comey’s replacement.
By all appearances, Rosenstein’s allegiances are strictly constitutional and institutional. If Trump’s choice for a new FBI director appears tainted in any way and if this is not an individual of unquestionable independence and integrity, it seems reasonable to expect that Rosenstein will be shooting off another memo.
Who knows? If he objects to Trump’s choice, maybe Rosenstein would even have the guts to do something virtually unheard of in this era: resign on a matter of principle.