The Ineligibility Clause is a provision in Article 1, Section 6, Clause 2 of the United States Constitution that puts a limitation on the employment of members of Congress from serving or holding other offices. It addresses a concern that Congress could increase the salary of a government position in anticipation of being appointed to that position. It also prohibits service in Congress while holding an other office to assure separation of powers.
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 increased 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.
The Articles of Confederation contained a similar provision.
A widely known conflict involving this clause concerned the appointment of Senator William B. Saxbe of Ohio to the post of United States Attorney General by then-President Richard Nixon, in the aftermath of the Saturday Night Massacre. The salary of the Attorney General had been increased in 1969, in the first year of the Senate term that Saxbe was still serving in 1973. Nixon's solution was to have Congress reduce the Attorney General's salary to the value it had before Saxbe took office. This maneuver, known as the "Saxbe fix", has been used a number of times since, although its legality is not universally agreed-upon.
When Barack Obama appointed Hillary Clinton as Secretary of State, she had previously voted as Senator to increase the salary of that position. Again, the Saxbe fix was used to reduce her salary and to allow her to serve in that position.