The union representing U.S. dockworkers has signaled that 45,000 members will walk off the job at midnight, kicking off a massive strike likely to shut down ports across the East and Gulf coasts.

Dockworkers at dozens of U.S. ports are digging in for a massive pay increase, seeking to flex their power in a strike that aims to strangle the flow of trade across much of the country.“This is going down in history what we’re doing here,