When police officers kill unarmed civilians, the Justice Department will often investigate to determine whether federal law was violated. When communities come into conflict with their police departments, Justice Department will often intervene to produce agreement on how to improve relations. When states and counties cut back on voting rights, the Justice Department’s Voting Section will determine whether to bring suit under the Voting Rights Act. When Presidents ask whether they can invade foreign countries without congressional approval, or torture terrorism suspects, or hold American citizens incommunicado without counsel, or use drones to assassinate them abroad, the answer will flow across the attorney general’s desk.

In law enforcement alone, the attorney general is the head of three separate agencies, each of them with sweeping powers—the Federal Bureau of Investigation, the Drug Enforcement Administration, and the Bureau of Alcohol, Tobacco and Firearms Enforcement. As leader of the Department’s civil division, the attorney general calls the shots on lawsuits against the government, and on suits brought by the government to recover funds or enforce federal laws. As head of the criminal division, the attorney general supervises the 93 U.S. attorneys around the country, and has sweeping discretion to decide which crimes are investigated and which are prosecuted. One of the most feared tools an attorney general wields is the H-bomb of criminal law, the federal grand jury, which a century ago the Supreme Court described as “a grand inquest, a body with powers of investigation and inquisition, the scope of whose inquiries is not to be limited narrowly by questions of propriety.” These grand juries may call any citizen before them, requiring each to appear alone, without counsel and, sometimes, without even the protection of the Fifth Amendment.

Who is the man Trump has chosen to wield this authority? Well, as noted, Jeff Sessions’s chief distinction to date is his rejection by the Senate Judiciary Committee—run at the time by the Republican majority—as a nominee for the federal district bench. At his confirmation hearing, former subordinates testified that, while he was a U.S. attorney, he called a black lawyer “boy” and warned him “be careful how you talk to white folks.” That he called the NAACP and the American Civil Liberties Union “un-American.” That he joked that he’d thought the Ku Klux Klan was “OK until I found out they smoked pot.”

Sessions never quite denied most of these charges, but insisted he was not a racist. Other witnesses testified that they had never seen a racist side of him. But what no one denied was his use of the power of the U.S. attorney’s office in Alabama to humiliate and intimidate African American voters. As Ari Berman chronicles the episode:

In the Democratic primary of September 1984, FBI agents hid behind the bushes of the Perry County post office, waiting for [famed Alabama Civil Rights advocate Albert] Turner and fellow activist Spencer Hogue to mail 500 absentee ballots on behalf of elderly black voters. When Turner and Hogue left, the feds seized the envelopes from the mail slots. Twenty elderly black voters from Perry County were bused three hours to Mobile, where they were interrogated by law-enforcement officials and forced to testify before a grand jury. Ninety-two-year-old Willie Bright was so frightened of “the law” that he wouldn’t even admit he’d voted. In January 1985, Jefferson Beauregard Sessions III, the 39-year-old US Attorney for the Southern District of Alabama, charged Turner, his wife Evelyn, and Hogue with 29 counts of mail fraud, altering absentee ballots, and conspiracy to vote more than once. They faced over 100 years in jail on criminal charges and felony statutes under the [Voting Rights Act]—provisions of the law that had scarcely been used to prosecute the white officials who had disenfranchised blacks for so many years. ... The trial was held in Selma, of all places. The jury of seven blacks and five whites deliberated for less than three hours before returning a not-guilty verdict on all counts.

Though rejected by the Judiciary Committee, Sessions went on to become attorney general of Alabama and then U.S. senator. And in those roles, he has fought tooth and nail against advances for racial equality, women’s rights, due process for immigrants, or voting rights.