Opinion writer

President Trump said he could shoot someone on Fifth Avenue and still count on his base’s support. Media, politicians and longtime political operatives predicted again and again that THIS (whatever the outrage of the day) would be the final straw. Not repealing Obamacare as promised? Nope, that had little if any effect. Equating neo-Nazis and anti-Nazi protesters or endorsing Roy Moore or siding with Russian President Vladimir Putin over his own intelligence advisers? Nope, nope and nope.

Expecting voters who didn’t care about or, worse, cheered his xenophobia, misogyny, know-nothingism and cruelty were not going to throw up their hands when he demonstrated his xenophobia, misogyny, know-nothingism and cruelty. So long as Trump railed at their favorite targets -- mainstream media, immigrants, government workers, zealous prosecutors and Democrats -- they were content.

Even when Trump was unable to change the status quo (e.g., repealing the Affordable Care Act), his fans could rationalize that the fault lay with others. When he didn’t do what he promised (pass a tax cut wholly directed at the middle class) and instead favored his cronies and rich friends, they could be mollified with the promise of higher wages and more jobs for everyone.

No revelation about Russia or Trump’s alleged criminality and/or unethical behavior moved them, either. They knew he was a swindler, a jerk and a provocateur, but he was their swindler, jerk and provocateur. And if he was too cozy with Russia or got help to win an election, why he was just outwitting the professional diplomats. Besides, what did it matter to them (his Fox News-saturated base) if Russia ran amok? It wasn’t like the Russians threatened their families.

However, where it got sticky for Trump was when he actually hurt his own base. It’s one thing not to make good on an unrealistic promise (cheaper, fairer, better health care for everyone!); it’s another to take money out of their pockets.

First came the tariffs that hit rural America hard. In the run-up to the midterms, we heard this kind of report: “The rust belt states he won over, in some cases very narrowly, are losing faith . . . [A]cross five of the rust belt states won by Trump in 2016 more voters believe the president’s tariffs on foreign imports are harmful to their families than beneficial.”

Then came the shutdown. The Post reports, “While Trump’s relationship with much of his base remains strong, two years after his inauguration his ties are fraying with voters . . . who voted in droves for Trump in key pockets throughout the industrial Midwest, flipping previously Democratic states to him in 2016.” Now, “The shutdown fight, as it has played out over the past month, is further eroding the president’s support among voters who like the idea of beefing up border security — but not enough to close the government.” Suddenly Trump’s destructive tendencies don’t seem amusing:

[F]ar from the nation’s capital and in an area not dominated by federal workers, the government shutdown is resonating in an unusual way. A trampoline park is giving government employees and their families an hour of free jumping. A local credit union is offering low-interest loans for furloughed employees who need to replace lost salaries.

Some local governments in the area are beginning to allow federal workers to defer payments on property taxes, utility bills and parking tickets. Food drives are being discussed to help Transportation Security Administration workers at Detroit’s airport, and a yoga studio is offering free classes for federal employees.

Working-class people understand in a very personal way that Trump really doesn’t care about them (“the shutdown standoff has also poked holes in Trump’s ability to say he cares for the working class, given that 800,000 federal employees and an additional number of contractors are going without paychecks.”).

When Trump’s voters finally get hit, then they may finally abandon him. (His support among key groups such as suburban men and white, non-college educated men dropped significantly.) We’d like to think all Americans care about one another, want to point to the president as a role model for their kids and fret when bad policies hurt the most vulnerable. Many Americans do operate that way -- just not Trump’s hardcore base. This is a zero-sum ground -- immigrants or them, elevation of Christianity or its eradication, white nationalism or white victimhood.

It’s fine in their book to watch Trump’s manic conduct infuriate experts and see hardship inflicted on immigrant children -- until it hits home.

This was in large part why Democrats successfully ran in 2018 on bread-and-butter issues including health care. Returning to a traditional Democratic economic record, they can remind even previously devoted Trump followers that the president has betrayed their interests.

Trump’s defenders should see some blinking red lights ahead. If the shutdown continues, if the trade war drags on and, worst of all, if the economy does backslide, Trump’s base may flee in greater numbers. This should be instructive for Democrats: Focus on the workers whom Trump won’t allow to be paid, reach out to farmers whose income Trump slashed and present the sort of economic program that Trump could have followed to great success. Call it fairness or justice or whatever you please. It is now plain for all to see that the one most responsible for rigging the system against ordinary Americans is Trump.

Read more:

The Post’s View: Surprise! We need the federal government.

Eugene Robinson: Above all else, Trump is a bully

E.J. Dionne Jr.: Hating the government won’t improve it

Paul C. Light: The shutdown has put a finger on the trigger of government failure. That should alarm you.

Karen Tumulty: Trump owns this shutdown debacle

Watch more: