WASHINGTON — President Bush nominated federal judge Michael Chertoff as new homeland security chief yesterday.

Chertoff, a former federal prosecutor who recently called for a new look at the tough terrorist detainee laws that he helped craft after the Sept. 11 attacks, is expected to win Senate approval easily. He has won confirmation three times during his career, as U.S. attorney in New Jersey, assistant attorney general and appellate judge.

"Mike has shown a deep commitment to the cause of justice and an unwavering determination to protect the American people," Bush said yesterday. "Mike has also been a key leader in the war on terror."

Chertoff would replace Tom Ridge, who helped build the new department after the terrorist attacks by combining 22 existing — and often competing — federal agencies. Ridge plans to step down Feb. 1.

Chertoff was the president's second pick for the job. Bush's first choice, former New York City police commissioner Bernard Kerik, withdrew last month citing immigration problems regarding a nanny.

"If confirmed as secretary, I will be proud to stand again with the men and women who form our front line against terror," Chertoff said yesterday.

Chertoff headed the Justice Department's criminal division at the time of the attacks, and helped develop the USA Patriot Act, which greatly expanded the government's surveillance and detention powers.

His role in crafting that law, a measure that has become a flash point for civil libertarians, is expected to bring sharp questioning in Senate confirmation hearings.

The American Civil Liberties Union said yesterday that as an architect of the act, Chertoff seemed to view the Bill of Rights "as an obstacle to national security rather than a guidebook for how to do security properly."

But since his appointment to the 3rd U.S. Court of Appeals in Philadelphia in June 2003, Chertoff has repeatedly called for taking a fresh look at the policy of detaining terror suspects and has questioned the extent to which that process should be open to judicial review.

"Two years into the war on terror, it is time to move beyond case-by-case development," Chertoff wrote in The Weekly Standard, a conservative publication, in December 2003. "We need to debate a long-term and sustainable architecture for the process of determining when, why, and for how long someone may be detained as an enemy combatant, and what judicial review should be available."

Sen. Joe Lieberman, ranking Democrat on the Senate Homeland Security and Government Affairs Committee, said he doubted Chertoff's role in crafting the Patriot Act "will be, in itself, a disqualification." More pressing, Lieberman said, are Chertoff's plans to manage a sprawling bureaucracy prone to infighting and competition with outside law-enforcement and intelligence agencies.

Rep. Chris Cox, R-Calif., chairman of the House Committee on Homeland Security, said Chertoff "is an outstanding selection, because he will quickly master the new parts of the job, and he has deep experience in so much of it already."