WASHINGTON - President Obama is morphing into George W. Bush, as administration attorneys repeatedly adopt the executive-authority and national-security rationales that their Republican predecessors preferred.

In courtroom battles and freedom-of-information fights from Washington to California, Obama's legal arguments repeatedly mirror Bush's: White House turf is to be protected, secrets must be retained, and dire warnings are wielded as weapons.

"It's putting up a veritable wall around the White House, and it's so at odds with Obama's campaign commitment to more open government," said Anne Weismann, chief counsel for Citizens for Responsibility and Ethics in Washington, a legal watchdog group.

There are some differences.

The Obama administration, for instance, has released documents on global warming from the Council on Environmental Quality that the Bush administration sought to suppress. Some questions, such as access to White House visitor logs, remain unresolved.

On policies that are at the heart of presidential power and prerogatives, however, this administration's legal arguments have blended into the other's. The persistence can reflect anything from institutional momentum and a quest for continuity to the clout of career employees.

A courtroom clash last week illustrated how Obama has come to emulate Bush.

Weismann's organization sued last year to obtain the notes from an interview that the FBI conducted with then-Vice President Dick Cheney.

The interview was part of an investigation into leaks concerning undercover CIA officer Valerie Plame, and the Bush administration vigorously fought release of the notes.

"The records contain descriptions of confidential deliberations among top White House officials, which are protected by the deliberative process and presidential communications privileges," Bush's Justice Department argued in an Oct. 10, 2008, legal brief.

"The new leadership of the department supports those arguments," Obama Justice Department attorney Jeffrey Smith told U.S. District Judge Emmet Sullivan during the oral argument Thursday.

Perspectives, of course, often change once candidates assume responsibility upon taking office. As a candidate, for instance, Obama opposed the Defense of Marriage Act, which defines marriage as between a man and a woman.

As president, however, he is following Bush's lead in defending in court the federal marriage law, which a California same-sex couple is challenging.

The law "reflects a cautiously limited response to society's still-evolving understanding of the institution of marriage," Assistant Attorney General Tony West declared in a legal filing June 11.

Every administration inherits lawsuits filed against its predecessor. The Solicitor General's Office, which represents the government in appeals, traditionally tries to hold a steady course. Personnel, too, stick around.

John Brennan, the CIA director's chief of staff during the Bush administration, is now advising Obama as a senior National Security Council staffer. Whatever the reasons, policy persists.

The Bush White House sought to keep e-mails secret. So does the Obama White House. The Bush White House sought to keep visitor logs secret. The Obama White House, so far, takes the same view.

Petaluma, Calif., resident Carolyn Jewel and the Electronic Frontier Foundation, a legal-activist group, sued the Bush administration over warrantless wiretaps. That administration said the lawsuit endangered national security.

In a legal brief April 3, the Obama administration agreed, citing potential "harm to national security."

The Bush administration objected to an American Civil Liberties Union request for access to documents that include photographs reportedly showing abuse of foreign prisoners held by the U.S. military in Iraq and Afghanistan.

The Obama administration said in April that it would release the photographs. Three weeks later, Obama reversed course and declared that "releasing them, I believe, would be to further inflame anti-American opinion and to put our troops in greater danger."