Iraqi Prime Minister is the designated fall guy for the poor Sunni Arab-Shia relations that have allowed ISIL to lead a Sunni Arab revolt in Iraq's north (May) and west (January).
But let's not forget that Maliki had reason to be wary of the Sunni Arabs. Stratfor notes this detail of our Awakening effort that bore fruit in 2007:
The [Iraqi Sunni Arab] tribal sheikhs basically used the jihadists as a tool, and when the United States made concessions to them -- and essentially bought them off -- they quickly turned on the jihadists, who were nearly destroyed. In a December 2013 assessment of the group, Stratfor noted that the Sunni sheikhs did not totally destroy the Islamic State in Iraq because they thought they might need to use the group as a tool again. This dynamic played a large role in the current insurgency. Many Sunni sheikhs were unhappy with al-Maliki's treatment of them, prompting them to allow the jihadists to rise in order to elevate their strategic position against Baghdad.
There is enough fault on both sides for the collapse of their mutual grudging trust without settling on the Shia Maliki as the guy who has to go to pay for the current crisis.
My only concern is that Iraqis choose their leader under their laws in order to give that leader legitimacy--not under pressure from us to bend to our will.
Which is another reason I wanted our troops to remain in Iraq after 2011. Without our safety net, mutual fear prompted escalating "defensive" actions that the other side rightly saw as threats.
And so here we are.