In his first 100 days in office, President Obama has not hesitated to chart a different course than his predecessor, George W. Bush.
Bush focused on the Iraq war; Obama has placed more of an emphasis on Afghanistan. Obama wants the government to have a role in reshaping the nation's health care system; Bush preferred to take smaller steps so individuals could buy private health insurance.
Then there's personal style; the cool, African-American lawyer from Chicago, and the back-slapping white rancher from Texas.
"It's Mars and Venus," says Thomas Mann, senior fellow in governance studies at the Brookings Institution, a Washington, D.C., think tank. "It's hard to find a more different contrast between the presidents."
Analysts such as David Rothkopf, a visiting scholar at the Carnegie Endowment for International Peace and a former Clinton administration trade official, suggest the difference boils down to their attitude toward government: Obama believes in a more activist government, while Bush leaned to finding free-market solutions.
"The Obama administration, I think, has truly closed the door on the Reagan era, when less government was always better," Rothkopf says. "The notion of leaving it to the market — that they know better — has had a stake put through its heart."
Some examples of overturned or modified Bush policies:
• Obama expanded federal support for embryonic stem cell research and overseas family planning clinics that counsel women about abortion. Bush believed federal funds should not support abortion, and he was opposed to extracting stem cell lines from human embryos.
• Obama set deadlines for withdrawing U.S. combat troops from Iraq and shutting down the prison for terror suspects at Guantanamo Bay, Cuba. Bush opposed hard and fast deadlines in both cases.
During Obama's recent overseas trip, a student in Istanbul told him that "some say just the face has changed" in the White House, but the "core is the same." He expressed worry about continuing conflict in the Middle East.
Obama responded that he is taking actions that represent real change, from setting a policy to withdraw U.S. combat troops from Iraq by August 2010 to pushing for an agreement to reduce carbon emissions that lead to global warming. He cautioned that change does not occur overnight.
"Moving the ship of state is a slow process," Obama told the student. "States are like big tankers; they're not like speedboats. You can't whip them around and go in a new direction."
Obama has been rebuked by former Bush administration officials — notably former vice president Dick Cheney — for undoing Bush-era policies on foreign policy and fighting terrorism. The emerging Obama-Bush team rivalry accelerated after Obama's recent decision to release memos outlining the CIA's harsh interrogation techniques of terrorism suspects.
"The CIA program is the single most important tool that the president (Bush) left in place to protect the country," former Bush speechwriter Marc Thiessen says.
Thiessen argues that some of Obama's foreign policies look similar to those imposed by Bush. He said Obama's plan to increase combat troops in Afghanistan resembles Bush's temporary increase of U.S. combat troops in Iraq. Thiessen also says both presidents want to use international pressure to block North Korea and Iran from obtaining nuclear weapons.
"On the domestic side," however, Thiessen says "they couldn't be more different."
Obama has "taken a completely different approach to government in terms of its size, scope, level of taxation and involvement in the markets and peoples' lives," says Ed Gillespie, a counselor to Bush.
Although tough economic times have made voters more receptive to the big government message, Gillespie says, in time it could lead to a "backlash" against an overly intrusive state.
Obama supporters such as Democratic political consultant Mark Mellman note the new president is merely responding to conditions that were inherited from Bush. "Obama is solving the problems," Mellman says. "That's a pretty big difference."