“If we don’t win this fight, there’s no other fight left.” That’s what New Jersey’s Republican Gov. Chris Christie said soon after taking office in 2010, when he faced off with the unions representing some 400,000 state employees. Mr. Christie knew what was at stake when he pushed through reforms that included changes in future pensions and greater employee contributions for health care.

For decades, politicians in New Jersey and states and localities across the country had kowtowed to the unions, giving them what they wanted in exchange for political support or, at least, to keep the peace with them. Over time, it became clear that the resulting burden ― high salaries, foolishly generous pensions and retirement benefits, and a lack of reform in areas like public schools is simply too great, in the long term, for governments to bear.

Unless political leaders stand up to the public sector unions, the entire country is going the way of Detroit.

There were good reasons why, long after the labor union movement gained momentum in the private sector, the idea of government employee unions remained unpopular. In the early history of the United States, most political jobs were based on patronage. That system had advantages, such as political accountability (you could blame the party in power if government workers didn’t do their jobs), but also disadvantages (high turnover, political favoritism, and the fact that government workers spent a lot of their worktime on politics).

To cure those problems, civil-service reforms were instituted, creating a corps of professional, nonpolitical government employees. They were generally well-respected, well-paid and had decent working conditions. In exchange they stayed out of politics and organizing.

By the 1950s, though, some politicians began to realize the potential advantages of politicizing the government workforce through unionization and forcing taxpayers to support a liberal political machine.

Increasingly, though, voters and political leaders see public sector unions as a threat. It’s not just taxpayers or Republicans, either. If nothing is done about the unfunded liability for future pensions and benefits, tax increases won’t be sufficient to cover the shortfall. That means government programs favored by liberals and Democrats will be threatened. In addition, it’s increasingly clear unions are the main obstacle to educational reform, without which the country faces a catastrophic shortage of skilled workers and intellectual firepower.