Major corporate lobbying groups, as well as organizations in conservative legal activist Leonard Leo’s orbit, are pressuring the Supreme Court to hamstring unions’ power to strike for better working conditions, according to legal briefs reviewed by us. The organizations are vilifying unions as violent and aggressive in efforts to support a case that could crush unions’ primary lever of power, at a time of surging strike activity and historically high support for unions among Americans.

Facing an increased union threat, a purportedly pro-union White House, and growing support for unions in Congress, corporations are turning to the Supreme Court — the corporate star chamber they helped fill with right-wing justices — to undercut worker power.

The case at issue, Glacier Northwest, Inc. v. International Brotherhood of Teamsters, deals with a 2017 strike at a concrete-mixing company. During the work stoppage, Teamsters who drove cement mixers walked off the job and left their trucks running so that the cement wouldn’t harden. But without the truck drivers, the company couldn’t deliver the cement, and it hardened.