But if McCain is running as a Bush stand-in, it's news to the McCain campaign and the White House. Although he almost always supported Bush's positions in Congress, McCain has done his best on the campaign trail to shun the widely unpopular Republican president, whose job approval rating sunk to a record low 28 percent in AP-Ipsos polls in April and July.
The last time the two Republicans were together was a closed-door McCain fundraiser in Arizona back in May. The only photo of the two was a departure shot at the airport. McCain seldom mentions the unpopular president whose job he seeks. The White House rarely talks about McCain.
So far McCain's strategy hasn't convinced the public. Six in 10 adults think McCain will follow the policies of Bush, including more than half of whites and nearly six in 10 independents, according to an AP-Yahoo News poll in late June.
McCain has begun airing a television ad in crucial states to defend himself against this perception. An announcer asserts, "We're worse off than we were four years ago." Pictures of the White House, the Capitol and the floor of the House of Representatives flash on the screen. The ad calls McCain "the original maverick."
While McCain spurns Bush as he hunts for general-election votes, the Obama camp melds the two together.
"Four more years of what we've had," warns Sen. Evan Bayh, D-Ind. "More of the same," echoes former Rep. Jim Leach of Iowa, a moderate Republican supporter of Obama. "The John McCain of 2000 wouldn't even consider voting for the John McCain of 2008," suggests Howard Dean, chairman of the Democratic National Committee.
The DNC sends out e-mail messages enumerating "100 Ways McCain and Bush are the Same."
The strategy plays on Bush's low approval ratings, public weariness with the Iraq war, high gasoline prices and general economic angst. It challenges McCain's reputation for independence and helps Obama push his theme of change.
Democrats acknowledge McCain's maverick past, as when he challenged Bush for the GOP nomination in 2000, but say those days are long gone.
"The price he paid for his party's nomination has been to reverse himself on position after position," Obama told a recent town-hall meeting in Indiana. "And now he embraces the failed Bush policies over the last eight years - politics that helped break Washington in the first place. And that doesn't exactly meet my definition of a maverick."
McCain did try to shore up his Republican base by promising to extend and expand Bush tax cuts he once opposed. He abandoned his opposition to offshore drilling. He made peace with television evangelists Pat Robertson and Jerry Falwell, whom he once called "agents of intolerance." And he vowed to appoint judges in the mold of Supreme Court Justices John Roberts and Samuel Alito, both Bush nominations.
But he hardly qualifies as a carbon copy of Bush.
Even now, he opposes Bush's support for drilling in the Arctic National Wildlife Refuge. Along with Obama, he backs more stem cell research and new restrictions on greenhouse gases that contribute to global warming. He's slammed the Bush administration's handling of Hurricane Katrina.
He opposed a 2005 administration-backed energy bill that gave big tax breaks to oil and gas companies, a measure Obama supported. The Obama campaign says that was because it contained lots of money for renewable energy and that the Illinois Democrat voted for an amendment, which failed, that would have scrapped the tax breaks for Big Oil.
McCain was an early critic of the administration's execution of the Iraq war. Long before Bush agreed last year, McCain pushed to send more U.S. troops to Iraq. This is one of his sharpest differences with Obama, who opposed the Iraq war from the start.
With Iraq and the U.S. having reached a preliminary agreement this week to withdraw American forces from Iraqi cities by next summer, McCain runs the risk of seeming even more belicose than Bush in handling an unpopular war.
McCain also has taken a much harder line than Bush on Russia's Vladimir Putin. A longtime Senate Armed Services Committee member, McCain strongly denounced the Russian military incursion into Georgia even before the president himself. McCain wants to expel Russia from the Group of Eight top industrial democracies.
In the Senate, McCain has often crossed swords with other Republicans on campaign-finance laws and their pet pork-barrel projects.
"I don't think the Obama campaign has done a particularly good job of linking McCain to George Bush," said Democratic pollster Doug Schoen, who has worked for former President Clinton and New York Mayor Michael Bloomberg and is unaffiliated with the Obama campaign. "I think Obama has not delivered the message with the degree of focus and repetition he needs to be successful in a presidential campaign."
McCain's overall Senate voting record lends support to the Democrats' case.
On legislation on which the president had a clear position, McCain voted with Bush 90 percent of the time from the day Bush took office in 2001 to when Congress left for its August 2008 recess, according to a study by Congressional Quarterly. For 2007, he voted with the president 95 percent of the time.
Obama voted with Bush 40 percent of the time since joining the Senate in 2005, CQ found.
Andrew Kohut, director of the nonpartisan Pew Research Center, said equating McCain with a third Bush term isn't having as much impact now as it might because "the conversation lately hasn't been about Bush and the state of the country. It's been more about Obama."
Also, Kohut said, despite McCain's roll-call record for supporting the president, "McCain is seen as a different kind of Republican. He's not seen as politically like Bush. When we ask people to rate the ideology of the candidates, Bush is way off to the right and McCain is sort of in the middle. So he can be seen as an agent of change, too."
For McCain, distancing himself from Bush while also courting his party's conservative base is a balancing act. Support for Bush is still strong in some conservative GOP quarters, and the Arizona senator doesn't want to alienate these Republicans.
"We've constantly got to pay attention to the need to excite our base," said McCain campaign manager Rick Davis. "At the start of the election cycle, the Republican party was pretty dispirited after the 2006 election. And in many cases, that remains true today."
James Thurber, a political scientist at American University, said trying to paint McCain as a Bush follower may yet pay off for Democrats. "All campaigns have to have a clear strategy, theme and message. And this is a pretty strong one. I think they'll keep hammering at it."