The Senators and Representatives shall receive a Compensation for their Services, to be ascertained by Law, and paid out of the Treasury of the United States. They shall in all Cases, except Treason, Felony and Breach of the Peace, be privileged from Arrest during their Attendance at the Session of their respective Houses, and in going to and returning from the same; and for any Speech or Debate in either House, they shall not be questioned in any other Place.
Senators and representatives set their own compensation. Under the Twenty-seventh Amendment, any change in their compensation will not take effect until after the next congressional election. Paying senators and representatives out of the federal treasury was a departure from the practice under the Articles of Confederation, where they were paid by the state in which they were elected.
Members of both houses have certain privileges, based on those enjoyed by the members of the British Parliament. Members attending, going to or returning from either house are privileged from arrest, except for treason, felony or breach of the peace. One may not sue a senator or representative for slander occurring during Congressional debate, nor may speech by a member of Congress during a Congressional session be the basis for criminal prosecution. The latter was affirmed when Mike Gravel published over 4,000 pages of the Pentagon Papers in the Congressional Record, which might have otherwise been a criminal offense. This clause has also been interpreted in Gravel v United States, (1972) to provide protection to aides and staff of sitting members of Congress, so long as their activities relate to legislative matters.
Clause 2: Independence from the executive.
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.
Senators and representatives may not simultaneously serve in Congress and hold a position in the executive branch. This restriction is meant to protect legislative independence by preventing the president from using patronage to buy votes in Congress. It is a major difference from the political system in the British Parliament, where cabinet ministers are required to be members of parliament.
Furthermore, senators and representatives cannot resign to take newly created or higher-paying political positions; rather, they must wait until the conclusion of the term for which they were elected. If Congress increases the salary of a particular officer, it may later reduce that salary to permit an individual to resign from Congress and take that position (known as the Saxbe fix). The effects of the clause were discussed in 1937, when Senator Hugo Black was appointed an associate justice of the Supreme Court with some time left in his Senate term. Just prior to the appointment, Congress had increased the pension available to Justices retiring at the age of seventy. It was therefore suggested by some that the office's emolument had been increased during Black's senatorial term, and that therefore Black could not take office as a justice. The response, however, was that Black was fifty-one years old, and would not receive the increased pension until at least 19 years later, long after his Senate term had expired.