Whatever you think of President Donald Trump’s “offer” of military assistance to riot-torn American cities — and I think it would be like pouring gasoline on a fire — understand it as pressure exposing an inconvenient truth:

Liberal Democratic governors and mayors have been mugged by reality. They’re suffering from shock, as violence and looting rage on. And what else do we see?

Their hands bitten to the bone by the hard political left that they once thought they could use and tame.

There were legitimately angry yet peaceful protests decrying the Minneapolis police killing of George Floyd, an African American man choked by a white cop. America was unified in sorrow for Floyd and in condemning police brutality.

But then the protests were hijacked by the politically violent. The anarchists and gangs of urban looters stained Floyd’s memory. And Americans bear witness to the chaos as they watch on their screens at home.

Police have been shot, overwhelmed by rioters. Lawyers (yes, lawyers) in New York were arrested after allegedly attempting to firebomb a police car with NYPD officers inside. A woman was savagely beaten trying to protect her business from looters in Rochester, New York, or was that Philadelphia?

Food stores in urban food deserts have been destroyed, as have the downtowns of many of the great cities, Chicago among them, which suspended its much-needed school meal pickup program for hungry children, most of them minorities.

And everywhere there are shards of broken glass, like shattered dreams, on the ground.

The looters roll on into the suburbs. And suburban soccer moms, with their guilt and their “Hate Has No Home Here” signs in their front lawns, download police scanner apps and wonder where they can buy a gun.

This is what happens when the people no longer trust their government to protect them.

Trump’s pressure obviously shook New York Gov. Andrew Cuomo awake enough to begin devouring New York City Mayor Bill de Blasio. Cuomo condemned de Blasio as a failure for not stopping the violence there and suggested he could have de Blasio removed from office.

“The NYPD and the mayor did not do their job last night. I believe that,” Cuomo fumed. “The police in New York City were not effective in doing their job last night. Period. They have to do a better job.”

They would do a better job if their mayor didn’t tell them to stand down, as happened in other cities too.

Power and violence abhor a vacuum and at the onset, Democratic governors and mayors did little if anything to stop the violence, which only encouraged the criminals. In Illinois and elsewhere, the mayors and governors backed off and watched as businesses were destroyed.

It started with Minneapolis Mayor Jacob Frey, who abandoned a police station. The mob burned the station in triumph, triggering yet more violence that spread across the nation.

This policy of giving safe space to the violent was immortalized by former Baltimore Mayor Stephanie Rawlings-Blake, who allowed 2015 protests over the death in police custody of Freddie Gray to warp out of control.

“It’s a very delicate balancing act,” she babbled as Baltimore burned. “… We also gave those who wished to destroy space to do that as well. And we worked very hard to keep that balance and to put ourselves in the best position to de-escalate.”

It did not de-escalate.

While Trump goes for the law-and-order-vote, the presumptive Democratic presidential nominee, Joe Biden, is conflicted.

He wants African American votes, without which Democrats can’t win in November. In his younger days, Biden understood that African Americans don’t like seeing their neighborhoods and stores destroyed. They don’t want their mothers having to take a bus to another neighborhood to get groceries.

But he also wants to keep Cuomo off his back and so, at a photo op at a black church in Delaware, Biden chattered on like some crazy blue jay, chirping out nonsense about teaching cops to shoot marauding criminals in the leg.

“When there’s an unarmed person, coming at him (police) with a knife or something, shoot them in the leg instead of in the heart,” Biden said. OK, Joe. Someone with a knife isn’t exactly unarmed. They’re armed, Joe. Have some more banana pudding.

Biden has moved far to the political left, but then, so have his establishment Democrats. They’re just as cynical as their Republican establishment counterparts. Establishment Democrats took a hard left turn in the hopes of herding or co-opting the hard left that is now the animating heart of their party.

They used “superdelegates” and Wall Street cash to rig the 2016 nomination for Hillary Clinton. And in 2020, they expected socialist Bernie Sanders to cave again without a real fight, and he did not disappoint.

When they lost the White House to Trump, they had to deflect blame away from themselves. They found their excuse in the Russia collusion hoax. No prosecutable evidence was found, but nevertheless establishment Democrats and their media handmaidens shrieked that Trump and Russia cost Hillary her dream.

But consider the establishment Democrats now, as violence has hijacked several George Floyd protests in key battleground states.

Now these mayors and governors cringe and make mewing sounds of appeasement, caught as they are between their hard-left political base and the growing disillusionment of voters. Some begin to devour themselves.

Winston Churchill, who understood them well, once said.

“Each one hopes that if he feeds the crocodile enough it will eat him last.”

John Kass is a columnist for the Chicago Tribune who also hosts a radio show on WLS-AM. His e-mail address is jskass@chicagotribune.com.