As part of a crackdown on legal marijuana, the Justice Department is set to roll back an Obama administration policy to not challenge state laws that allow people to use pot for medical and recreational uses, according to an official familiar with matter who was not authorized to comment publicly ahead of a formal announcement. Attorney General Jeff Sessions has long signaled his disagreement with the previous administration's stance on pot, which did not challenge state laws as long as marijuana sales did not conflict with federal law enforcement policies.
