More than 4,400 ships bring nearly $400bn worth of goods through the ports of Los Angeles and Long Beach every year, a crucial link in the global supply chain of factories, warehouses, docks, highways and rail lines. Most blue-collar workers along the chain have seen their wages slashed with the quick rise of global trade. But the longshoremen who move the goods the shortest distance, between ship and shore, have shrewdly protected pay that trumps that of many white-collar managers.