At issue is Section 206 of the Labor Management Relations Act of 1947, better known as the Taft-Hartley Act. The law authorizes a president to seek a court order for an 80-day cooling-off period for companies and unions to try to resolve their differences.

Biden has said, though, that he won’t intervene in the strike.

Taft-Hartley was meant to curb the power of unions

The law was introduced by two Republicans — Sen. Robert Taft of Ohio and Rep. Fred Hartley Jr. of New Jersey — in the aftermath of World War II. It followed a series of strikes in 1945 and 1946 by workers who demanded better pay and working conditions after the privations of wartime.

President Harry Truman opposed Taft-Hartley, but his veto was overridden by Congress.

In addition to authorizing a president to intervene in strikes, the law banned “closed shops,” which require employers to hire only union workers. The ban allowed workers to refuse to join a union.

Taft-Hartley also barred “secondary boycotts,” thereby making it illegal for unions to pressure neutral companies to stop doing business with an employer that was targeted in a strike.

It also required union leaders to sign affidavits declaring that they did not support the Communist Party.

Presidents can target a strike that may “imperil the national health and safety”

The president can appoint a board of inquiry to review and write a report on the labor dispute — and then direct the attorney general to ask a federal court to suspend a strike by workers or a lockout by management.

If the court issues an injunction, an 80-day cooling-off period would begin. During this period, management and unions must ”make every effort to adjust and settle their differences.”

Still, the law cannot actually force union members to accept a contract offer.

Presidents have invoked Taft-Hartley 37 times in labor disputes

According to the Congressional Research Service, about half the time that presidents have invoked Section 206 of Taft-Hartley, the parties worked out their differences. But nine times, according to the research service, the workers went ahead with a strike.

President George W. Bush invoked Taft-Hartley in 2002 after 29 West Coast ports locked out members of the International Longshore and Warehouse Union in a standoff. (The two sides ended up reaching a contract.)

Biden has said he won’t use Taft-Hartley to intervene

Despite lobbying by the National Association of Manufacturers and the National Retail Federation, the president has maintained that he has no plans to try to suspend the dockworkers’ strike against ports on the East and Gulf coasts.

On Wednesday, before leaving Joint Base Andrews for an air tour of North Carolina to see the devastation from Hurricane Helene, Biden said the port strike was hampering efforts to provide emergency items for the relief effort.

“This natural disaster is incredibly consequential,” the president said. “The last thing we need on top of that is a man-made disaster — what’s going on at the ports.”

Biden noted that the companies that control East and Gulf coast ports have made huge profits since the pandemic.

“It’s time for them to sit at the table and get this strike done,” he said.

Though many ports are publicly owned, private companies often run operations that load and unload cargo.

William Brucher, a labor relations expert at Rutgers University, notes that Taft-Hartley injunctions are “widely despised, if not universally despised, by labor unions in the United States.”

And Vice President Kamala Harris is relying on support from organized labor in her presidential campaign against Donald Trump.

If the longshoremen’s strike drags on long enough and causes shortages that antagonize American consumers, pressure could grow on Biden to change course and intervene. But experts like Brucher suggest that most voters have already made up their minds and that the election outcome is “really more about turnout” now.

Which means, Brucher said, that “Democrats really can’t afford to alienate organized labor.”