In race which drew significant public attention, he defeated former Jackson mayor Dale Danks in the Democratic primary and won the general election.

Moore then negotiated Barnett's resignation and secured his cooperation into an investigation into other illegal contributions from utility companies to public service commissioners.

Beginning in 1982, lawyers in Mississippi began filing tort cases against asbestos manufacturers and construction companies in pursuit of damages against adversely-impacted individuals.

He hired attorney Richard Scruggs—a former law school classmate who had worked on several asbestos cases—on a 25 percent contingency to serve as the state's lead counsel.

State Auditor Steve Patterson felt the arrangement was unethical, as Moore had no specific legal authority to contract out the work of his office to private attorneys and Scruggs had donated $20,000 to his 1991 campaign fund.

[23] After consulting friends and family, Moore declared his candidacy for the seat on August 27, calling his decision "the toughest thing I've ever done in my life" but saying he felt the state required "the strongest voice we could get in Washington.

[27] In the summer of 1993 attorney Mike Lewis approached law school classmate Moore with the suggestion of plaintiffs seeking damages against cigarette manufacturers to cover the medical costs of smoking-related illnesses, which were often incurred by the government.

As Scruggs began forming a team of attorneys in private practice to discuss the idea, Moore's office drafted plans for a lawsuit.

Increasingly worried that they might lose the case, the companies sent representatives to negotiate a settlement with Moore and the 39 other state attorneys general who had joined the lawsuit.

[39] The national settlement required the approval of the U.S. Congress, and though Moore, Scruggs, and others spent a year lobbying for the body to codify the agreement, their assent was never given and the deal was not carried out.

Reflecting on the outcome in 2022, Moore expressed disappointment that the trust fund had not lasted long but pointed to declines in tobacco use as worthy of celebration.

[12][43] In 1997 the National Law Journal named him its Lawyer of the Year[44][45] and the American Medical Association granted him a Dr. Nathan Davis Award for promoting public health.

[47] In February 1989, Moore settled a lawsuit against the state over the drawing of judicial districts in a manner which allegedly diluted the political strength of black voters.

[50] In 1998, The Clarion-Ledger published the transcript of a 1980s interview with Samuel Bowers, an erstwhile leader of the Ku Klux Klan who was convicted for his involvement in the murder of civil rights activist Vernon Dahmer.

[52] Later that year, the U.S. Federal Bureau of Investigation turned over thousands of documents related to their original inquiry of the case to the attorney general's office.

[54] In 2000, the attorney general told journalist Jerry Mitchell of his disappointment that the state had never prosecuted the murders and said, "It is our belief at this point that Preacher Killen was one of the masterminds of the Neshoba County killings.

[1][59] He declared his intention to enter private legal practice but left open the possibility of running for other offices such as governor or a U.S. Senate seat in the future.

In 2003, Moore began representing clients who sued Purdue Pharma, claiming the company had gotten them or family members addicted to prescription opioid painkillers.

In 2014 Ohio Attorney General Mike DeWine contracted a group of lawyers led by Moore to build a case against several drug suppliers.

In May 2017 they filed a lawsuit against Purdue Pharma, Teva Pharmaceutical Industries, Janssen, Endo, and Allergan, accusing them of concealing the addictiveness of opioids and violating Ohio laws concerning fair business practices.

[5] In 2018, Moore was hired by the government of Hillsborough County, Florida, to lead its lawsuit against 14 companies for alleged violations of state law with regards to the aggressive marketing of opioid drugs.