OUTRAGE OVER THE brutal killing of George Floyd has rightly heightened public scrutiny of police union resistance to desperately needed reforms. Less understandable is the assumption that the police are an anomaly among the most powerful public employee unions when it comes to opposing reform.

Of course the actions of other public sector unions don’t lead to the deaths of innocent people, so it’s understandable that the obstructionism in this case inspires a unique level of fury.

Yet too often, pushing back against common-sense reforms is just what politically influential public employee unions do, and a steady stream of campaign contributions allows them to be very effective. But it also sets up a troubling dynamic in which contract negotiations amount to elected officials bargaining with their benefactors. In a democracy, citizens must guard against any group amassing too much power.

The unique power public employee unions wield in Massachusetts is symbolized by the so-called Pacheco Law, which makes it virtually impossible to privatize any function performed by state employees. The law also covers the MBTA, and its impact became painfully clear when the Commonwealth created a Fiscal and Management Control Board (FMCB) after the T collapsed in the snow in 2015.

One of the emergency powers granted to the FMCB was a three-year exemption from the Pacheco Law. It wasn’t hard for the board to find functions that could benefit from competition. Contracting out the MBTA’s cash counting operation cut costs by 70 percent and dramatically improved performance.

Warehousing and logistics proved to be a similar story. Amazon could move a part from San Francisco to Boston in 24 hours, but it took the MBTA 82 hours to move one from Everett to Lynn. After the service was contracted out, inventory accuracy improved from 50 percent to nearly 90 percent, virtually all deliveries are made in 10 hours or less, two-hour emergency parts delivery is available 24/7/365, and the T is saving 40 percent over its previous costs.

Despite stories like these, extending the MBTA’s Pacheco Law exemption wasn’t even proposed when it expired in 2018.

Preserving monopolies is not the only way in which Massachusetts public employee unions resist reform. The MBTA Retirement Fund is a monument to the power of the Carmen, the largest of the T’s 28 unions. Despite the transit authority’s legendarily precarious finances, many of its employees still retire in their 40s, enjoy far more generous pensions than their state counterparts and, unlike state employees, also collect Social Security.

Nor is the power to block progress limited to transit unions. In 1993, state leaders dealt teachers’ unions a rare setback when the Commonwealth enacted a landmark education reform law over their opposition. In return for a large infusion of new funding, the law demanded high standards and accountability from all K-12 public education stakeholders.

It worked. By 2005, we became the only state whose students finished first in the country in reading and math at both grade levels tested on the National Assessment of Educational Progress (NAEP), known as “the Nation’s Report Card.” In 2007, Massachusetts eighth graders tied for first in the world on international science testing.

But teachers’ unions never relented in their opposition to the reforms, and ultimately succeeded at eliminating an independent school district accountability office and stunting the growth of charter public schools that dramatically outperform the district schools from which their students come. The Commonwealth also adopted weaker academic standards and tests. Other than increased funding, little remains of policies that brought historic success.

The results of this retreat shouldn’t be surprising. State NAEP scores have been falling for a decade and last year the decline accelerated. Eighth-grade math scores fell more than those in 38 states and Washington, DC, and the decline in fourth-grade math was worse than in 40 states and DC. Alarmingly, fourth- and eighth-grade reading scores fell by about twice as much as the math scores.

It isn’t that public employee unions are evil. Like any entity made up of humans, outsized influence makes the lure of using that power to advance their own narrow interests irresistible.

Many Americans live in places where public employee unions wield little clout. But in states like Massachusetts, police are hardly alone when it comes to using enormous political influence to block common-sense reforms. The brutal killing of George Floyd should remind voters of the threat concentrated power poses to a healthy democracy.

Charles Chieppo is a senior fellow at Pioneer Institute, a Boston-based think tank.