Constitution
Article I, Section 3: The Senate
Section 3 builds the Senate: two senators per state, six-year staggered terms, the Vice President's tie vote, and the Senate's power to try impeachments.
The text
The Senate of the United States shall be composed of two Senators from each State, chosen by the Legislature thereof, for six Years; and each Senator shall have one Vote.
Immediately after they shall be assembled in Consequence of the first Election, they shall be divided as equally as may be into three Classes. The Seats of the Senators of the first Class shall be vacated at the Expiration of the second Year, of the second Class at the Expiration of the fourth Year, and of the third Class at the Expiration of the sixth Year, so that one third may be chosen every second Year; and if Vacancies happen by Resignation, or otherwise, during the Recess of the Legislature of any State, the Executive thereof may make temporary Appointments until the next Meeting of the Legislature, which shall then fill such Vacancies.
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.
The Vice President of the United States shall be President of the Senate, but shall have no Vote, unless they be equally divided.
The Senate shall chuse their other Officers, and also a President pro tempore, in the Absence of the Vice President, or when he shall exercise the Office of President of the United States.
The Senate shall have the sole Power to try all Impeachments. When sitting for that Purpose, they shall be on Oath or Affirmation. When the President of the United States is tried, the Chief Justice shall preside: And no Person shall be convicted without the Concurrence of two thirds of the Members present.
Judgment in Cases of Impeachment shall not extend further than to removal from Office, and disqualification to hold and enjoy any Office of honor, Trust or Profit under the United States: but the Party convicted shall nevertheless be liable and subject to Indictment, Trial, Judgment and Punishment, according to Law.
Note: The first two paragraphs were modified by the 17th amendment, under which senators are elected by the people of each state and vacancies are filled by election.
In plain English
Clause 1: composition. Each state has two senators with one vote each, serving six-year terms. The original text had state legislatures choose them; since 1913 the voters do.
Clause 2: staggered terms. The first Senate was split into three classes so that one-third of the seats come up every two years. The Senate is therefore a continuing body: it never turns over all at once.
Clause 3: qualifications. A senator must be at least 30, a citizen for nine years, and an inhabitant of the state when elected, a step above the House's 25 and seven.
Clause 4: the Vice President. The Vice President presides over the Senate but votes only to break a tie.
Clause 5: other officers. The Senate chooses its own officers, including a President pro tempore to preside when the Vice President is absent.
Clause 6: impeachment trials. The Senate alone tries impeachments. Senators sit under oath, the Chief Justice presides when the President is on trial, and conviction requires two-thirds of the senators present.
Clause 7: punishment. The penalty on conviction is limited to removal from office and, if the Senate chooses, disqualification from future federal office. Criminal prosecution in the courts remains available separately.
What the Founders said
Equal representation of the states in the Senate was the price of the Constitution. Large states wanted representation by population in both houses; small states wanted equality. The Connecticut Compromise, adopted on July 16, 1787 by a single state's margin, gave the House to population and the Senate to the states.
In Federalist No. 62 Madison wrote that the equal vote "is at once a constitutional recognition of the portion of sovereignty remaining in the individual States, and an instrument for preserving that residuary sovereignty." Election by state legislatures served the same end: senators answered to the state governments, which gave those governments a voice in national lawmaking.
The Senate was also meant to be a check on haste. Federalist No. 62 warned against "mutable" legislation, and Federalist No. 63 described the Senate as a defense for the people against their own temporary errors, a body whose longer terms and smaller size would steady the House. The higher age and citizenship requirements served the same purpose.
On impeachment, Federalist No. 65 explained why the Senate, rather than the Supreme Court, should try the case: the offenses are political in nature, and the tribunal needed both independence and numbers.
How the courts have read it
- Nixon v. United States (1993): a challenge by a federal judge to the Senate's use of a committee to take evidence was a nonjusticiable political question; the word "try" gives the Senate sole discretion over its trial procedures.
- Powell v. McCormack (1969) and U.S. Term Limits, Inc. v. Thornton (1995): read together with Section 2, the age, citizenship and inhabitancy requirements are exclusive; neither a chamber nor a state may add more.
Why it matters now
The Senate is regularly criticized as undemocratic because Wyoming and California have the same two votes. That criticism misreads the design. The United States is a union of states as well as a nation of people, and the Senate is where the states, as states, are represented. Article V protects that equality even from ordinary amendment: no state may lose its equal suffrage without its own consent.
The 17th Amendment changed how senators are chosen, and in doing so it removed the state governments' direct voice in Washington. Whether that was wise remains a live debate on the right, and it helps explain why federal mandates on states became easier to pass in the twentieth century.
The six-year term and the staggered classes still do what the Framers intended: they make the Senate slower and more deliberative than the House. That frustrates whichever party wants to move quickly. It is also the reason a single election cannot remake the whole government overnight.