For now, Mr. Anwar’s wife, Wan Azizah Wan Ismail, is expected to be deputy prime minister, the second-highest post in the new government.
Mr. Mahathir has also said that he would clear the way for the criminal prosecution of Mr. Najib, who is accused of taking hundreds of millions of dollars in government funds.
Mr. Najib has been embroiled for years in a scandal involving billions of dollars that disappeared from a government investment fund that he once led, 1Malaysia Development Berhad. The United States Justice Department concluded that $3.5 billion from the Malaysian fund was laundered through financial institutions in the United States and spent on items like expensive real estate, jewelry, paintings and the production of movies.
Cynthia Gabriel, executive director of the Center to Combat Corruption and Cronyism in Kuala Lumpur, said she expected the new government to properly investigate Mr. Najib and the missing funds, and to begin cooperating with the Justice Department and other foreign inquiries.
“There is a lot of work to be done to undo the years of unbridled power,” Ms. Gabriel said. “But for now, the power has been returned to the Malaysian people, as we have ushered in a two-party system.”
The ouster of Mr. Najib was all the more striking in a region where the solidification of autocratic government has seemed to be the rule, including arbitrary killings, imprisonment, and crackdowns on the media.
From President Rodrigo Duterte’s deadly drug war in the Philippines, to violence against Rohingya Muslims in Myanmar, and Prime Minister Hun Sen’s campaign to crush Cambodia’s democratic opposition, it has been a tough period for democracy and human rights throughout Southeast Asia.