Section 151.121(c) does not apply to—

(a) The Governor or Lieutenant Governor of a State or an individual authorized by law to act as Governor;

(b) The Mayor of a city;

(c) A duly elected head of an executive department of a State, municipality, or the District of Columbia, who is not classified under a merit or civil service system of a State, municipality, or the District of Columbia;

(d) An individual holding elective office;

(e) Activity in connection with a nonpartisan election; or

(f) Candidacy for a position of officer of a political party, delegate to a political party convention, member of a National, State, or local committee of a political party, or any similar position.