Section 6, Clause 02
Article I. The Congress
Section 6. Rights and Disabilities of Members
Clause 1. Compensation and legal protection
Clause 2. Independence from the executive
Clause 2. Disabilities of Members
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.