The Constitution imposes several qualifications and restrictions on Congressional service, most notably in Article I, sections 2 and 3 (which sets out age, citizenship, and residency requirements), and the Incompatibility Clause in Article I section 6 which forbids members of Congress from also serving in the executive or judicial branches. Designed to foreclose patronage and corruption, it also effectively precludes a parliamentary-style of government in which office holders have both legislative and executive powers. Interestingly, it did not forbid simultaneous executive and judicial service – reflected by examples such as John Jay and John Marshall (both of whom served as Secretary of State while also serving on the Supreme Court). Such a practice would now be viewed as constitutionally suspect.