Homeland Security Secretary Alejandro Mayorkas issued a memo Tuesday ordering immigration and border agents to stop raids and arrests at workplaces of suspected illegal aliens. “The deployment of mass worksite operations, sometimes resulting in the simultaneous arrest of hundreds of workers, was not focused on the most pernicious aspect of our country’s unauthorized employment challenge: exploitative employers,” Mayorkas said in the three-page memo (pdf). “These highly visible operations misallocated enforcement resources while chilling, and even serving as a tool of retaliation for, worker cooperation in workplace standards investigations.” The memo is directed at the U.S. Immigration and Customs Enforcement, U.S. Citizenship and Immigration Services Troy, and U.S. Customs and Border Protection. It calls the agencies to shift their focus toward “unscrupulous employers who exploit the vulnerability of undocumented workers.” Such employers are paying substandard wages, imposing unsafe working conditions, and facilitating human trafficking and child exploitation, Mayorkas wrote. The substandard wages create an …