Louis Brandeis was nominated to serve as an associate justice of the Supreme Court of the United States by U.S. President Woodrow Wilson on January 28, 1916, after the death in office of Joseph Rucker Lamar created a vacancy on the Supreme Court. Per the Constitution of the United States, Brandeis' nomination was subject to the advice and consent of the United States Senate, which holds the determinant power to confirm or reject nominations to the U.S. Supreme Court.

Brandeis' nomination attracted significant opposition and controversy. This partially arose from his reputation and record as a lawyer of being regarded a "people's lawyer" hostile towards corporate interests. Brandeis had a record of opposing monopolies, criticizing investment banks, and advocating for workers' rights. Concerns were raised about the "radicalism" of Brandeis. Opposition also arose from antisemitism due to Brandeis being the first Jewish nominee to the Supreme Court of the United States. The nomination was opposed by corporate leaders, such as J. P. Morgan Jr. William Howard Taft (a former U.S. president and former American Bar Association president) organized opposition to the nomination among American Bar Association leaders. Taft and six other former presidents of the American Bar Association sent a letter to the Senate Committee on the Judiciary opposing the nomination. The nomination also came into strong opposition from members of the Boston Brahmin, an upper class group of the city of Boston that was associated with Harvard University. Among the most prominent in opposing the nomination were A. Lawrence Lowell (the president of Harvard University) and Henry Lee Higginson (a prominent patron of Harvard University). Despite this, all but one member of the faculty of the Harvard Law School endorsed the nomination. Felix Frankfurter, among the Harvard Law School faculty member, was a particularly proactive supporter of the nomination. The nomination received liberal and progressive support. In addition, many prominent members of the American Jewish community supported the nomination.

Brandeis' nomination was subject to near-unprecedented confirmation hearings conducted by the Senate Committee on the Judiciary. The 125-day gap between his nomination and the full-Senate vote on confirming him to the court is by far the longest such gap for any U.S. Supreme Court nomination that was brought to a confirmation vote. The nomination ultimately received positive reports from both a subcommittee of the Judiciary Committee and from the full Judiciary Committee. Brandeis was confirmed to the court on June 1, 1916, in a 47–22 vote.

Nomination by President Wilson

On January 28, 1916, President Woodrow Wilson nominated Louis Brandeis to fill the associate justice seat on the Supreme Court of the United States left vacant by the death in office of Joseph Rucker Lamar. The nomination was then referred the Senate Committee on the Judiciary.Chilton, p. 1 Wilson's nomination of Brandeis was regarded as a great surprise. He had never come up in speculation about what individuals might fill the vacancy. It had not been expected that Wilson, up for what seemed like a difficult reelection battle eight months later in the 1916 United States presidential election, would nominate a controversial individual. It was reported that several senators gasped when the nomination was announced to the Senate chamber.

The New York Times''' reporting shortly after the nomination was made credited Thomas Watt Gregory, the U.S. attorney general, with having made the successful recommendation to Wilson that Brandeis be appointed to the court. In making his selection, Wilson ignored the tradition of informing, and usually receiving the approval, of the U.S. Senators representing the nominee's home state. In Brandeis' case, the senators representing his home state of Massachusetts were Republican senators Henry Cabot Lodge and John W. Weeks. In fact, the only U.S. senator that Wilson, a Democrat, had his administration consult before announcing the selection of Brandeis was Robert La Follette, a progressive member of the Republican Party. Attorney General Gregory met with La Follette days after Justice Lamar's death and inquired as to whether La Follette would consider crossing party lines to vote to confirm Brandeis, which La Follette enthusiastically declared that he would. Brandeis had only been told of his nomination several days before it was formally made.

Brandeis, dubbed the "people's lawyer", was a controversial figure for his challenging of monopolies, criticism of investment banks, his advocacy for workers' rights, and his advocacy for protecting civil liberties. He was regarded as a "trust buster". Brandeis was among the nation's most noted Progressive reformers. Brandeis was also the first person of Jewish descent ever nominated the Supreme Court of the United States. President Wilson had commonality with Brandeis over their skepticism of large corporate power, with Wilson having been a stronger supporter of antitrust laws than either Theodore Roosevelt or William Howard Taft, who had been his main opponents in the 1912 United States presidential election. Brandeis had been an influential advisor, political confidante, and friend of Wilson since Wilson's 1912 campaign and had shaped Wilson's "The New Freedom" agenda. When he took office in 1913, Wilson had considered appointing Brandeis as his U.S. attorney general. However, corporate executives, particularly those from the banking and legal establishment of Brandeis' native Boston, launched active opposition to the appointment of Brandeis. Among motivations for this was backlash to Brandeis' legal battles against them, as well as antisemitic opposition to the prospect of Brandeis serving as the first Jewish attorney general. Consequentially, Wilson had decided at that time that he would be too controversial of an appointee.Lief, Alfred. Brandeis: The Personal History of an American Ideal, Stackpole Sons (1936), pp. 257−258 However, Wilson retained a desire to appoint Brandeis to either his Cabinet or to the Supreme Court.

Taking what appeared to be a political risk with his choice surprised many, especially considering the wide view that Wilson would already have a challenge being reelected. Incumbents had had difficulty getting reelected in previous decades. Since Ulysses Grant's reelection in 1872, only once had a president been elected in two consecutive elections (William McKinley in 1900). Additionally, Democrats were not viewed as favored in presidential elections at the time. Since the United States Civil War, the only Democratic wins in presidential elections had been Wilson's own 1912 victory, and Grover Cleveland's non-consecutive victories in the 1884 and 1892 elections. Furthermore, Wilson had won the 1912 election against a divided Republican Party, whose base of support split much of its vote between the party's nominee, Taft, and the third party run of Roosevelt. With a united Republican Party in the 1916 presidential election, it seemed even more possible that Wilson would be defeated.

While general political logic had caused many to see it as a surprise that Wilson would nominate such a controversial individual to the Supreme Court months before he was up for reelection as president, there may have been political calculations in his decision to nominate Brandeis. A likely motivation for Wilson's selection Brandeis to be his nominee for the Supreme Court may have been a desire to shore up his credentials as a political progressive before the upcoming 1916 presidential election. Some at the time of the nomination also believed he might also have been seeking to shore up Jewish support for his reelection, with The Nation writing on February 10, 1916, "old-fashioned politicians" read the nomination as, "bait for the Hebrew vote at the coming election."

The nomination of a Jewish man to the Court came, notably, amid a high point in antisemitism in the United States. The backdrop of the era included incidents such as the recent lynching of Leo Frank and the prominence of the Ku Klux Klan.

Opposition to the nomination

Brandeis' nomination ignited an intense confirmation battle. Brandeis' nomination evoked a polarized and vocal reaction. The widespread attention and intense fight over the nomination was in contrast to most preceding Supreme Court nomination processes, which had been low-key and quiet. It was considered among the most contentious nominations up to that point.

Many opponents took issue with the "radicalism" of Brandeis. The nomination quickly received strong conservative backlash. The Sun newspaper of New York City expressed outrage that Brandeis, who they regarded as a radical, had been nominated for appointment to, "the stronghold of sane conservatism, the safeguard of our institutions, the ultimate interpreter of our fundamental law". Corporate leaders, such as J. P. Morgan Jr., stood in opposition to the nomination. The New York Times wrote in its front-page story after the nomination was made,

Brandeis' later successor on the court, William O. Douglas, wrote many years later that the nomination of Brandeis "frightened the Establishment," because he was, "a militant crusader for social justice." He also wrote that, "the fears of the Establishment were greater because Brandeis was the first Jew to be named to the Court."The New York Times and The Wall Street Journal were among the press outlets that most prominently opposed the nomination. The New York Times claimed that having been a noted "reformer" for so many years, Brandeis would lack the "dispassionate temperament that is required of a judge."Todd, Alden L. Justice on Trial: The Case of Louis D. Brandeis, McGraw-Hill (1964), p. 73 The Wall Street Journal's editor, Clarence W. Barron, strongly opposed Brandeis' nomination. The Wall Street Journal wrote of Brandeis, "In all the anti-corporation agitation of the past, one name stands out... where others were radical, he was rabid."Klebanow, Diana, and Jonas, Franklin L. People's Lawyers: Crusaders for Justice in American History, M.E. Sharpe (2003) The New York Times conceded that even Brandeis' harshest detractors noted that he was a remarkably skilled lawyer, but many still contended that his abilities as a lawyer did not make him suited for the Supreme Court.

The opposition of Massachusetts U.S. Senator Henry Cabot Lodge was seen as a major concern, as it had been conventional for presidents to have first received the approval of the two Senators from a Supreme Court nominee's home state before making a nomination, or to at least notify them of their intention prior to making the nomination. Wilson had not done either. Lodge may have been able to block the nomination, as senior senator from Massachusetts, had the senator invoked the customary rule of Senatorial courtesy. However, Lodge did not do so despite holding both Wilson and Brandeis in strong public disdain. While he did urge American Bar Association leadership to oppose the nomination, Lodge did not play a major role in leading the opposition to the nomination, despite many anticipating that he would. One theory that was presented for why he did not was to not imperil his reelection in the upcoming 1916 United States Senate election in Massachusetts, fearing repercussions from Jewish and Catholic voters if he more actively opposed the nomination. Lodge himself had accused Wilson of only selecting Brandeis in order to win over Jewish voters in important states.

Upon the nomination's initial announcement, a number of Democratic senators voiced dissatisfaction with the nomination.