Biden was born on November 20, 1942, at St. Mary's Hospital in Scranton, Pennsylvania, to Catherine Eugenia "Jean" Biden (nee Finnegan) and Joseph Robinette "Joe" Biden Sr. He was the first of four siblings in a Catholic family, with a sister, Valerie, and two brothers, James and Frank, following. His mother was of Irish descent, with roots variously attributed to County Louth or County Londonderry. His paternal grandparents, Mary Elizabeth (Robinette) and Joseph H. Biden, an oil businessman from Baltimore, Maryland, were of English, French, and Irish ancestry.

During his first years in the Senate, Biden focused on legislation regarding consumer-protection and environmental issues and called for greater accountability on the part of government. In mid-1974, freshman Senator Biden was named one of the 200 Faces for the Future by Time magazine, in a profile that mentioned what had happened to his family and characterized Biden as "self-confident" and "compulsively ambitious". Biden became ranking minority member of the U.S. Senate Committee on the Judiciary in 1981. In 1984, he was Democratic floor manager for the successful passage of the Comprehensive Crime Control Act; civil libertarians praised him for modifying some of the Act's provisions, and it was his most important legislative accomplishment at that point in time. He first considered running for president in that year, after he gained notice for giving speeches to party audiences that simultaneously scolded and encouraged Democrats. Regarding foreign policy, during his first decade in the Senate, Biden focused on arms control issues. In response to the refusal of the U.S. Congress to ratify the SALT II Treaty signed in 1979 by Soviet leader Leonid Brezhnev and President Jimmy Carter, he took the initiative to meet the Soviet Foreign Minister Andrei Gromyko, educated him about American concerns and interests, and secured several changes to address objections of the Foreign Relations Committee. When the Reagan administration wanted to interpret the 1972 SALT I Treaty loosely in order to allow the Strategic Defense Initiative to proceed, Biden argued for strict adherence to the treaty's terms. He clashed again with the Reagan administration in 1986 over economic sanctions against South Africa; he received considerable attention when he excoriated Secretary of State George P. Shultz at a Senate hearing because of the administration's support of that country, which continued to practice the apartheid system.

Answer the following question by taking a quote from the article: Why did he change his mind?
characterized Biden as "self-confident" and "compulsively ambitious".