I've been warning for some time that Baghdad's government wouldn't last much longer without a drastic change (see here and here), but the political crisis took a dramatic turn for the worse this week.
The highlight of this growing crisis was the storming of Iraq's parliament.

Lawmakers fled Saturday after protestors stormed into the parliament.
About 60 lawmakers, mostly from the minority Kurdish and Sunni parties, flew out of the capital for Irbil and Suleymania, in the northern autonomous Kurdish region.
“It was dangerous for all of us,” one parliament official told VOA, speaking on condition of anonymity out of fear of retaliation. Some lawmakers were beaten, he said.
The official said thousands of protesters were still in the so-called International Zone Sunday, parked outside the major government buildings.
“It is dangerous,” the parliament official said. “At any time, the protesters could attack any embassy, any institution they want, or abuse anybody passing by.

Iraqi's lawmakers were trapped in the basement for hours, and then beaten as they fled the building.

This happened just days after VP Joe Biden visited the Green Zone.
Parliament was already politically paralyzed before this happened.
Some are describing this as a coup, and because of this fact Prime Minister Haider al-Abadi has ordered the arrest of the protesters after declaring a state of emergency. This is a risky move because the local security forces have strong sympathies with the protesters.

There are no indications that any actual arrests have taken place.

The political chaos in Baghdad has caused Shia militias, militias that are already outside of Baghdad's control, to withdraw forces from the front lines in the battle against ISIS in order to secure the streets of Baghdad.
That's not good news because the Mosul offensive was already failing.

From a sandbagged hilltop outpost here, you can see the front line of the Islamic State in the muddy brown houses of Al-Nasr, a village on the next ridgeline, about a mile-and-a-half west. The Iraqi army was supposed to have captured this target a month ago. But the offensive was repelled....
“I have limited forces,” says Maj. Gen. Najim Abed al-Jabouri, the Iraqi commander for the Mosul offensive. He has about 5,000 troops but says that he needs a force six times larger and an attack plan that hits Mosul from all sides. The recent political chaos in Baghdad has hurt army morale and made planning more difficult, he says. “We try to move toward the correct way, but the corruption in Iraq is very deep.”

It appears increasingly likely that any serious attempt at recapturing Mosul will have to wait.
Very belatedly, the American news media is waking up to the flaws in our Iraqi allies (things I pointed out 18 months ago).

ISIS has been seriously weakened over the past year or so, but that only makes the weaknesses of it's enemies more apparent.
Baghdad's chronic political problems become more urgent the further ISIS is driven from Baghdad. The most obvious chronic political problem is the lack of reconciliation with the Sunnis, but another chronic problem is the increasing divisions with their Kurdish allies.

Hostilities broke out over the weekend between two groups considered critical components of the ground war. Troops from the predominantly Shiite Muslim militias – known as the popular mobilization units or PMUs – reportedly attacked the home of an officer with the Kurdish fighting force known as the peshmerga, according to media reports. The militiamen claimed they were retaliating against an unprovoked peshmerga attack.
Fighting escalated into Sunday as peshmerga troops launched mortars and Shiite militias lit two of the Kurdish unit's tanks on fire.

It appears increasingly likely that Iraqi Kurdistan will declare independence from Baghdad before the year is out.