While many constitutional amendments have added to the rights held by Americans, changed the balance of power between the federal government and states, or altered elections for the President, the structure of Congress in the written Constitution has barely been touched since 1791. The only constitutional amendment to do so in a substantial way is the Seventeenth Amendment, which removed from state legislatures the power to choose U.S. Senators and gave that power directly to voters in each state.
According to James Madison, giving state legislatures the power to choose Senators provided a “double advantage,” both “favoring a select appointment, and of giving to the State governments such an agency in the formation of the federal government as must secure the authority of the former.” The Federalist No. 62. George Mason argued that state legislative selection gave states the power of self-defense against the federal government. Wendell Pierce argued that the contrast between a state legislatively-appointed Senate and a popularly-elected House would increase the types of interests represented in the federal government. By requiring the consent of two different constituencies to any legislation—the people’s representatives in the House and the state legislatures in the Senate—the composition of the Senate was seen as essential to the system of bicameralism, which would require “the concurrence of two distinct bodies in schemes of usurpation or perfidy.”
Whether state legislative appointment was included in the Constitution to protect state governments, though, is a matter of some dispute. Contemporary legal scholar Terry Smith argues that it was merely the result of the intersection of two other goals, the Great Compromise giving states equally-weighted votes in the Senate and a desire to limit popular representation.
Either way, state legislatures were not given other powers that might have allowed them to more directly control Senators, like the power to recall Senators or to instruct them on how to vote. As a result, scholars like William Riker and Larry Kramer have argued that state legislatures exerted little control over Senators at any point, although more recent work by Todd Zywicki has argued that this is overblown and state legislative control did have a substantial effect on the way the Senate operated. (See Todd Zywicki’s individual explainer on the Seventeenth Amendment.)
However, starting in roughly the 1830s and then more dramatically after the Civil War, the vision the Founders had—in which state legislatures would deliberate over the selection of Senators—began to fray. First, politicians seeking Senate seats began campaigning for state legislative candidates in a process known as the “public canvass.” The result was that state legislative races became secondary to Senate races. The most famous instance of this was the race for Senate in Illinois in 1858, in which Abraham Lincoln faced off with Stephen Douglass despite neither being on the ballot. In 1890s, many states started holding direct primaries for Senate, reducing the degree of influence state legislatures had over selection. Some states went further and began using something known as the “Oregon System,” under which state legislative candidates were required to state on the ballot whether they would abide by the results of a formally non-binding direct election for U.S. Senator. By 1908, twenty-eight of the forty-five states used the Oregon System or some other form of direct elections.
The push for the Seventeenth Amendment occurred both in state legislatures and the House of Representatives. Between 1890 and 1905, thirty-one state legislatures passed resolutions either calling on Congress to pass an amendment providing for the direct election of senators, to hold a conference with other states to work on such an amendment, or to have a constitutional convention such that the direct elections for Senator could be included in a newly drawn Constitution. Amendments to the Constitution providing for direct elections passed the House in each session between 1893 and 1912.
But several influential Senators managed to hold off the Amendment for more than two decades. Their effort was aided by a decision to link the Amendment to a controversial effort to remove from Congress the power to pass rules governing federal elections under the Elections Clause of Article I. Eventually, though, the issues were split and it passed both Houses in 1912 and was ratified by the States in 1913.
The arguments for the Seventeenth Amendment sounded in the case for direct democracy, the problem of hung state legislatures, and in freeing the Senate from the influence of corrupt state legislatures. The Progressive movement that pushed the Seventeenth Amendment supported other constitutional changes at federal, state, and local levels like the initiative and referendum, non-partisan elections, and unicameral legislatures (although there has never been a major effort to provide for democratic election of federal judges).
The Seventeenth Amendment was seen as part of a broader effort to make an end-run around the control that parties, machines, and special interests had over state legislatures. (Ironically, however, big city party machines supported the Seventeenth Amendment, largely because state legislative apportionment gave greater representation to rural areas due to districting decisions in the absence of “one person, one vote” and because machine-controlled cities could more easily mobilize voters. Many big special interests supported it as well.) William Randolph Hearst famously hired muckraking journalist David Graham Phillips to write an expose, “The Treason of the Senate,” which played a major role in debates around the Seventeenth Amendment. The popular perception that Senate seats could be bought in backrooms of state legislatures fueled support for direct elections. Further, several Senate seats remained open for years when state legislatures couldn’t agree on a choice, although the importance of this is somewhat questionable and was attributable to a federal statute that required that Senators be elected by a majority of state legislators, not a plurality, in state legislatures, a requirement that notably was not included for popular elections in the Seventeenth Amendment.
Further, supporters of the Amendment argued that races for Senate swamped interest in state issues in state legislative races, reducing the accountability of state legislatures on any issue other than the identity of Senators. (See David Schleicher’s individual explainer on the Seventeenth Amendment.)
By the time the Seventeenth Amendment finally passed, it was wildly popular. In recent years, however, the Seventeenth Amendment has come under some criticism from conservatives like Justice Antonin Scalia, columnist George Will, and a host of Republicans in Congress for removing an important power from state legislatures. Further, the implications of the Amendment—particularly its effect on appointments following vacancies—have become the subject of some dispute.
But despite this, the change wrought by the Seventeenth Amendment seems quite secure and remains the only major change to the structure of Congress.