WASHINGTON — President-elect Barack Obama plans to use his executive powers to make an immediate impact when he takes office, perhaps reversing Bush administration policies on stem cell research and domestic drilling for oil and natural gas.

John Podesta, Obama's transition chief, said yesterday Obama is reviewing President Bush's executive orders on those issues and others as he works to undo policies enacted during eight years of Republican rule. He said the president can use such orders to move quickly on his own.

"There's a lot that the president can do using his executive authority without waiting for congressional action, and I think we'll see the president do that," Podesta said. "I think that he feels like he has a real mandate for change. We need to get off the course that the Bush administration has set."

Podesta also said Obama is working to build a diverse Cabinet. That includes reaching out to Republicans and independents — part of the broad coalition that supported Obama during the race against Republican John McCain. Defense Secretary Robert Gates has been mentioned as a possible holdover.

Obama was elected on a promise of change, but the nature of the job makes it difficult for presidents to do much that has an immediate impact on the lives of average people. Congress plans to take up a second economic aid plan before year's end — an effort Obama supports. But it could be months or longer before taxpayers see the effect.

Obama could use his executive powers to at least signal that Washington is changing.

"Obama's advantage, of course, is he'll have the House and the Senate working with him, and that makes it easier," said Carl Tobias, a law professor at the University of Richmond. "But even then, having an immediate impact is very difficult to do because the machinery of government doesn't move that quickly."

Presidents long have used executive orders to impose policy and set priorities. One of Bush's first acts was to reinstate full abortion restrictions on U.S. overseas aid. The restrictions were first ordered by President Reagan and stayed in place until President Clinton lifted them soon after he occupied the Oval Office. It wouldn't be surprising if Obama did the same.

Executive orders "have the power of law and they can cover just about anything," Tobias said in a telephone interview.

Bush used his executive power to limit federal spending on embryonic stem cell research, a position championed by opponents of abortion rights who argue that destroying embryos is akin to killing a fetus. Obama has supported the research in an effort to find cures for diseases such as Alzheimer's. Many moderate Republicans also support the research, giving it the stamp of bipartisanship.

Two top House Republicans said there is a willingness to try to work with Obama to get things done. But they said to expect Republicans to serve as a check against the power held by Obama and Democratic leaders in Congress.

"It's going to be a cheerful opposition," said Rep. Mike Pence, R-Ind.