A federal judge has blocked several key measures of South Carolina’s anti-immigrant law, the latest in a series of judgments against similar measures nationwide. On Thursday, U.S. District Judge Richard Gergel froze a number of provisions he said would breach the federal government’s sole authority to oversee immigration enforcement. The measures include rules forcing police officers to check the immigration status of individuals if the officer has “reasonable suspicion” they are undocumented. The Justice Department and a coalition of civil rights groups had sued to prevent the law from taking effect next month.