the term “public official” means Member of Congress, Delegate, or Resident Commissioner, either before or after such official has qualified, or an officer or employee or person acting for or on behalf of the United States, or any department, agency or branch of Government thereof, including the District of Columbia, in any official function, under or by authority of any such department, agency, or branch of Government, or a juror;

the term “person who has been selected to be a public official” means any person who has been nominated or appointed to be a public official, or has been officially informed that such person will be so nominated or appointed; and

the term “official act” means any decision or action on any question, matter, cause, suit, proceeding or controversy, which may at any time be pending, or which may by law be brought before any public official, in such official’s official capacity, or in such official’s place of trust or profit.