PHOENIX -- Democrats already are regularly attacking John McCain for offering what they characterize as a third George W. Bush term.

But a new Theodore Roosevelt presidency might be closer to the mark.

McCain, the four-term Republican senator from Arizona and presumptive GOP presidential nominee, is promising an administration that reflects "conservative principles, values and vision." He also says his administration would have a powerful environmental bent, in the Roosevelt tradition.

At this early stage, the names and faces that would flesh out a McCain White House remain pure speculation. After all, McCain insists he hasn't started seriously thinking about a running mate yet. And there's still a general election to win against a yet-to-be-determined Democratic opponent. But political experts and analysts already are contemplating what a McCain Cabinet might look like.

Some common guesses include well-known McCain allies and even past rivals in key positions:

• Sen. Joe Lieberman, I-Conn., in a prominent job, possibly even secretary of state.

• Former Sen. Fred Thompson, R-Tenn., as attorney general.

• Former New York Mayor Rudy Giuliani as homeland security secretary.

• Former Sen. Phil Gramm of Texas as treasury secretary.

• Former Arkansas Gov. Mike Huckabee as health and human services secretary.

For his part, McCain last week said he'd be looking for Cabinet members who "just share my conservative philosophy and views: less government, less regulation, lower taxes." But he also volunteered that conservationism would be a priority, saying he would hope "to preserve the great natural treasures of the West and our state and do whatever we can to protect our environment."

"I return to kind of the Teddy Roosevelt outlook toward things," McCain said.

McCain has long identified Roosevelt, president from 1901 to 1909, as a political idol. Roosevelt made national parks and nature preserves a priority, and McCain has drawn fire from conservative Republicans for opposing oil exploration in the Arctic National Wildlife Refuge and for sponsoring legislation to address climate change.

McCain would tap business titans

McCain has dropped other hints about his Cabinet along the campaign trail.

Over the past year, he often has talked about approaching U.S. business leaders to serve their country by taking on federal-government responsibilities. He specifically has mentioned Fred Smith of FedEx, John Chambers of Cisco Systems, Steve Ballmer of Microsoft and billionaire investor Warren Buffett as possible Cabinet members.

Bureaucracies such as the hapless Federal Emergency Management Agency, whose limitations were exposed in 2005 by Hurricane Katrina, could use a dose of private-sector ingenuity and know-how, McCain has said.

"I would go out to the smartest and best people in America, no matter what their party affiliation," McCain said last year at a town-hall meeting in Gilford, N.H. "There are some very successful people in this country who have done a great deal and become very rich while doing it. And I'm going to those people — the John Chambers and the Steve Ballmers and the Warren Buffetts and all those people — and say, 'Look ... you've done very well in this country. Now give back something to your country.' "

Like Roosevelt, McCain shares reformer tendencies and aims to sic his best and brightest appointees on, among other things, the Defense Department, where he sees rampant waste and inefficiency in its acquisition process.

A Pentagon focus

Some observers said they could possibly see McCain keeping on Defense Secretary Robert Gates, who has been in the job for only a little more than a year. McCain and Gates generally are in alignment on the Iraq war, a major emphasis of McCain's. But McCain, a former Navy pilot with years of national security experience, is expected to exude heavy influence on the Pentagon regardless of who holds the post.

"Like (former President Dwight) Eisenhower, McCain would probably be his own secretary of defense," said John J. "Jack" Pitney Jr., who teaches politics and government at Claremont McKenna College in California.

McCain also has vowed to immediately shutter the Guantanamo Bay detention camp and has clashed with the Bush White House over the treatment of suspected terrorists. That means any Justice Department and Defense Department officials who justified the use of what McCain considers torture are sure to be dispatched in his administration.

"I wouldn't see a big shakeup at the Pentagon, but I would expect that most of the political appointees would be gone as a matter of course, but especially if they'd been involved in the decisions about torture," said James Pfiffner, a presidency scholar and professor of public policy at George Mason University in northern Virginia.

Bush staffers would leave

In general, few observers expect McCain to keep many, if any, Bush administration figures. Even if Bush didn't continue to poll poorly, new presidents traditionally clean house.

"He's going to want his own people in there," Pitney said of McCain. "During the campaign, he'll probably want to emphasize that his administration would be a new beginning. I think he realizes that a lot of Bush holdovers would get him off to a bad start in public opinion."

Sen. Jon Kyl, R-Ariz., a McCain supporter, predicted wholesale turnover regardless of McCain's feelings about the current Cabinet.

"Very few people in a political position expect to stay into the next administration — virtually none," Kyl said. "If John McCain comes in and says, 'Gee, I'd like to have you stay,' maybe somebody would be willing to stay, but the expectation is that the job ends at the end of this year."