It is difficult to overstate the hostility of the Roberts court to organized labor and the rights of American workers.

Under John Roberts, who became chief justice in 2005, the court has made it harder for workers to bring suit against employers collectively, limited the power of workers to hold employers responsible for discrimination on the job, ended the ability of public sector unions to require dues from nonmembers who benefit from collective bargaining and struck down a California law that allowed unions to recruit workers on the property of agricultural employers.

In pretty much any given conflict between an employer and a group of workers, you can count on Roberts and his Republican allies on the court to side with the employer.

We saw this dynamic at work last week when the court issued its decision in Glacier Northwest v. International Brotherhood of Teamsters Local Union No. 174. The case involves a struggle in Washington state between workers represented by the Teamsters and their employer, a concrete manufacturer.

In its lawsuit, Glacier alleged that its workers timed a 2017 strike so that it would begin after some of the company’s mixing trucks were already filled with wet concrete, a perishable material. Glacier’s non-unionized workers were able to remove the concrete before the trucks were significantly damaged, but the company sued the Teamsters in state court anyway for damages relating to lost revenue from the wrecked concrete.

The union countered, citing the right to strike. It also noted that the damaged concrete was essentially spoilage of a product, for which unions have not generally been held liable. The Washington State Supreme Court dismissed the suit on the grounds that the dispute was “pre-empted by the National Labor Relations Act.”

The Supreme Court took Glacier’s appeal. And in an opinion joined by Roberts and Justices Sonia Sotomayor, Elena Kagan and Brett Kavanaugh, Justice Amy Coney Barrett held that unions are liable for damages during strikes under federal labor law when they take “affirmative steps to endanger” the employer’s property rather than “reasonable precautions to mitigate that risk.” She also sent the case back to the Washington State court for further litigation.

In a separate concurrence joined by Neil Gorsuch, Clarence Thomas said the Supreme Court should reconsider its 1959 decision in San Diego Building Trades Council v. Garmon, which held that state courts are barred from handling claims concerning conduct that is “arguably” covered by the National Labor Relations Act. Under Garmon, employers must first receive a favorable ruling from the National Labor Relations Board if they want to sue a union for striking in state court. Tossing Garmon would bring labor law much closer to its pre-N.L.R.A. status quo, when conservative judges treated union actions as little more than criminal conspiracies to harm employers. Justice Samuel Alito also filed a concurrence in support of the majority.

The divide among the liberal justices was especially striking. The sole dissent came from Justice Ketanji Brown Jackson, who argued that the ruling would “erode the right to strike” and undermine the oversight of workplace law by the N.L.R.B. “Workers are not indentured servants, bound to continue laboring until any planned work stoppage would be as painless as possible for their master,” she wrote. “They are employees whose collective and peaceful decision to withhold their labor is protected by the N.L.R.A. even if economic injury results.”

It is possible that Justices Kagan and Sotomayor joined Barrett’s opinion in a strategic move meant to foreclose a more expansive decision from Thomas, Gorsuch and Alito. If so, it may ultimately prove a short reprieve in the face of a conservative majority that is eager to undermine a set of interests — labor’s interests — and a set of rights — workers’ rights — that it does not respect.

One point that must be emphasized is how, with its war on workers, the Roberts court is only acting in the Supreme Court’s historical capacity as an agent of capital. At times, the court has taken an expansive view of the civil and political rights of the American people. But it has rarely been a friend to the right of workers to organize and act in their own interests.

In the decade before the passage of the National Labor Relations Act, for example, the Supreme Court under William Howard Taft issued rulings constraining the ability of unions to act and organize, subjecting union actions to antitrust law and upholding restrictions on speech that targeted unions and other pro-labor organizations.

In other words, the Supreme Court is first and foremost the leading defender of property within our political order. And how could it be otherwise? The Constitution itself was written, in part, to protect the rights of property in the face of democracy and the spirit of egalitarianism. Even a more liberal Supreme Court than the one we have now would eventually find itself acting against labor, for the simple reason that the American political system was not built with the interests of workers in mind.

Which means, as our actual court has once again made clear, that the struggle for the emancipation of labor does not, as Samuel Gompers once wrote, take place in an “ideal world.” Instead, “we are in the bitter struggles of an unjust society.” If labor is ever going to get what it needs, it probably won’t be with the helping hand of a judge or a justice.