5 U.S.C. § 7325

The Office of Personnel Management may prescribe regulations permitting employees, without regard to the prohibitions in paragraphs (2) and (3) of section 7323(a) and paragraph (2) of section 7323(b) of this title , to take an active part in political management and political campaigns involving the municipality or other political subdivision in which they reside, to the extent the Office considers it to be in their domestic interest, when— (1) the municipality or political subdivision is— (A) the District of Columbia; (B) in Maryland or Virginia and in the immediate vicinity of the District of Columbia; or (C) a municipality in which the majority of voters are employed by the Government of the United States; and (2) the Office determines that because of special or unusual circumstances which exist in the municipality or political subdivision it is in the domestic interest of the employees and individuals to permit that political participation.