Can you become a U.S. senator if you have dual citizenship?

Question

Can you become a U.S. senator if you have dual citizenship? Or is there a law that says you can only become a U.S. senator if you have only one citizenship and you are a U.S. citizen? I know you can be a naturalized U.S. citizen and become a Senator, but I am not sure if you need to renounce your second citizenship in order to become a Senator.

Answer 1

The U.S. Constitution merely requires that you be a U.S. citizen, that you be at least 30 years of age, that you have resided nine years in the United States, and that you currently reside in the state from which you are elected, to be a U.S. Senator.

The courts have held that extra-constitutional qualifications for the office may not be imposed.

The Supreme Court of the United States has affirmed the historical understanding that the Constitution provides the exclusive qualifications to be a Member of Congress, and that neither a state nor Congress itself may add to or change such qualifications to federal office, absent a constitutional amendment. Powell v. McCormack, 395 U.S. 486, 522 (1969); U.S. Term Limits, Inc. v. Thornton, 514 U.S. 779, 800-801 (1995); Cook v. Gralike, 531 U.S. 510 (2001).

(Source: Congressional Research Service).

Therefore, a dual citizen can be a U.S. Senator under U.S. law.

This said, the oath of office involved in becoming a U.S. Senator is something that would be considered a voluntary relinquishment of the individual's non-U.S. citizenship by many countries. Under U.S. law:

[W]ith the exception of formal denaturalization, a United States citizen can lose his citizenship only if he voluntarily performs an act that is “in derogation of allegiance to the United States,” 42 Op. Att’y Gen. 397, 400 (1969), and that was committed with the intent to relinquish United States citizenship. See Vance v. Terrazas, 444 U.S. 252, 261 (1980). “[A]n act which does not reasonably manifest an individual’s transfer or abandonment of allegiance to the United States cannot be made a basis for expatriation.” 42 Op. Att’y. Gen. at 400.

Although the Supreme Court has definitively held that Congress cannot provide by statute for involuntary expatriations, it has upheld Congress’ authority to prescribe by statute the types of acts that Congress considers to be generally “highly persuasive evidence . . . of a purpose to abandon citizenship.” See Nishikawa v. Dulles, 356 U.S. at 139; Vance v. Terrazas, 444 U.S. at 261, 265. These acts are set forth in § 349 of the Immigration and Nationality Act, 8 U.S.C. § 1481. One of these specified acts is a “formal renunciation of nationality before a diplomatic or consular officer of the United States in a foreign state.” 8 U.S.C. § 1481(a)(6).

Other specified acts include: obtaining naturalization in a foreign state; taking an oath or making an affirmation or other formal declaration of allegiance to a foreign state; serving in the armed forces of a foreign state; serving in an office or employment under the government of a foreign state that requires assumption of the nationality of that state or a declaration of allegiance to that state; or committing an act of treason against the United States. Id. § 1481(a)(l)-(4), (7).

Thus, under U.S. law, the oath of office required to serve as a U.S. Senator if made to a state other than the United States (e.g. in connection with being sworn in as a Mexican Senator), would end the dual citizenship of the person being sworn in to public office, and make them only a citizen of the country in which that elected official held public office (in this example, of Mexico).

Many countries cause dual citizenship to be relinquished under similar circumstances.

Answer 2

The US Constitution states the qualifications for being a Senator (Article I, section 3, clause 3)

No Person shall be a Senator who shall not have attained to the Age of thirty Years, and been nine Years a Citizen of the United States, and who shall not, when elected, be an Inhabitant of that State for which he shall be chosen

Congress is not empowered to change these requirements.

Edit: The Constitution is saying, to be a Senator, you must:

• Be at least 30 years old
• Been a US citizen for at least 9 years (implying: immigrants OK).
• actually live in the State you represent when elected (implied: you would live in the national capitol during your term, since travel in 1789 was very difficult).