When Boston police officers declared an illegal strike in September 1919, Massachusetts Governor Calvin Coolidge condemned the men for “desertion of duty,” and upheld the decision of the commissioner of police to fire the strikers and hire replacements. “There is no right to strike against the public safety,” he declared, “by anybody, anywhere, any time.”

Coolidge’s resolute stand made him a national hero overnight. In November he was reelected in a landslide. A year later he was Warren Harding’s running mate on the GOP national ticket, and won election to the White House in his own right in 1924.

The principle that public employees cannot go on strike, and that there is no right to collective bargaining in the public sector, was once endorsed across the political spectrum. “A policeman has no more right to belong to a union than a soldier or a sailor,” editorialized The New York Times during the Boston strike. For decades, that was the mainstream Democratic view, too. “The process of collective bargaining, as usually understood, cannot be transplanted into the public service,” President Franklin D. Roosevelt affirmed in 1937. He recognized that government is not just another employer, and that empowering labor unions to negotiate with public officials is an invitation to abuse. Ronald Reagan, an FDR admirer and the only labor union leader to become president, upheld that principle in 1981, when he fired 11,000 air-traffic controllers who refused to end an illegal strike — and earned strong public approval for his decision.

How things have changed. Labor unions and collective bargaining in the public sector are now routine, and when public employees walk off the job politicians rush to praise them.

In Chicago, teachers have been on strike since Oct.17, leaving 350,000 students and their parents in the lurch. In Dedham, Mass., teachers went on strike last week, forcing the town to close schools on Friday. Public school teachers have also walked off the job recently in Park County, Col. and Murphysboro, Ill. Yet far from condemning the teachers unions and their members for abandoning their public jobs, elected officials shower them with acclaim.

Notwithstanding the immense disruption the teachers’ walkout has inflicted on Chicago, Elizabeth Warren, Bernie Sanders, and other leading Democrats have gone out of their way to encourage the strikers and endorse their demands. In Massachusetts as in most states, government employees are legally barred from striking. Dedham’s scofflaw teachers faced no criticism from the Bay State’s political bigfeet, however. Both US senators came out in support of the strikers, and Representative Joe Kennedy III showed up at the Dedham picket line with coffee and doughnuts. “In me, you have an ally, you have a champion,” he gushed.

Lost in all this adulation is the reason strikes by government workers are against the law: Unlike job actions in the private sector, strikes in the public sector are not economic weapons deployed against private management. They are political weapons deployed to bring distress upon innocent third parties.

When 46,000 United Auto Workers recently went on strike against General Motors, their goal wasn’t to heap misery on the nation’s car buyers. It was to win a larger share of GM’s healthy profits through improved pay and benefits. As with any private sector strike, both labor and management faced the discipline of the market. The longer the strike lasted, the more business GM lost and the more paychecks union members went without. In the private sector, there are limits to the concessions labor can demand. Companies need profits to survive, and outrageous labor costs can cause a company to lose sales, eliminate jobs, or, if worse comes to worst, go out of business.

But such checks and balances don’t exist when government workers go on strike.

It isn’t management that gets squeezed when teachers, air-traffic controllers, or trash collectors walk off the job. It’s ordinary citizens. Striking government employees don’t seek economic equity from cash-laden corporate management; they seek to make the public miserable, and thereby increase political pressure on public officials to accede to the union’s demands.

Strikes in the public sector have nothing to do with getting management to share its wealth, and everything to do with extracting more money from taxpayers who are deprived of bargaining power in the process. Everybody wants more money and more lavish benefits, but the compensation of government employees is a matter of public policy. That policy should be crafted openly, as other government policies are. It shouldn’t be held hostage to pressure from lawbreaking employees, and no government official should be required to negotiate with special interest lobbies — which is what public-sector unions amount to — in setting the terms and conditions of government employment.

FDR, Reagan, and Coolidge were right, even if it is unfashionable to say so: Public workers have no right to strike, and collective bargaining should have no place in government employment. The system we live with now is rigged — rigged against taxpayers and against democratic fairness. If only we had political leaders unafraid to say so.

(Jeff Jacoby is a columnist for The Boston Globe).