Article I, Section 6, Clause 2:
No Senator or Representative shall, during the Time for which he was elected, be appointed to any civil Office under the Authority of the United States, which shall have been created, or the Emoluments whereof shall have been encreased during such time; and no Person holding any Office under the United States, shall be a Member of either House during his Continuance in Office.
This second part of the second clause elicited little discussion at the Convention and was universally understood to be a safeguard against executive influence on Members of Congress and the prevention of the corruption of the separation of powers.1 Congress has at various times confronted the issue in regard to seating or expelling persons who have or obtain office in another branch. Thus, it has determined that visitors to academies, regents, directors, and trustees of public institutions, and members of temporary commissions who receive no compensation as members are not officers within the constitutional inhibition.2 Government contractors and federal officers who resign before presenting their credentials may be seated as Members of Congress.3
One of the more recurrent problems which Congress has had with this clause is the compatibility of congressional office with service as an officer of some military organization – militia, reserves, and the like.4 Members have been unseated for accepting appointment to military office during their terms of congressional office,5 but there are apparently no instances in which a Member-elect has been excluded for this reason. Because of the difficulty of successfully claiming standing, the issue has never been a litigable matter.6