Revised stem
Timothy is a licensed private bar-prep tutor in a state that requires a license to offer paid bar-exam preparation services. A state statute provides that the Tutor Licensing Commission may revoke a tutor's license if it finds that the tutor used a place of business for an illegal purpose. Federal narcotics agents arrested Timothy at his tutoring office, alleging that he sold methamphetamine from the office in violation of federal law. The local United States Attorney declined to prosecute, and the charges were dropped. Nevertheless, the Commission initiated a proceeding to revoke Timothy's license on the ground that he used his tutoring office for illegal drug sales. At the hearing, the only evidence against Timothy consisted of written, signed statements from unnamed informants, none of whom were present or available for questioning. The statements asserted that each informant purchased methamphetamine from Timothy at the tutoring office. Based solely on those statements, the Commission found that Timothy used his place of business for an illegal purpose and ordered his license revoked. In a suit to set aside the revocation, Timothy's best constitutional argument is: