President campaigns for McCain

The liberal group MoveOn.org also unveiled a commercial Tuesday that links images of Bush and McCain over the theme song of the "Patty Duke Show," a 1960s sitcom about identical teenage cousins who "laugh alike, they walk alike, at times they even talk alike."

Bush and McCain last appeared together publicly the day after the Arizona senator sewed up the nomination in early March.

The president welcomed the GOP's new standard-bearer to the White House at a brief Rose Garden news conference. It was a somewhat awkward scene. McCain fidgeted and said repeatedly that he'd welcome campaigning with Bush "in keeping with the president's heavy schedule." Bush, for his part, seemed eager to hand off the reins, saying the McCain would be making the hard decisions and "I'm going to be in Crawford with my feet up."

Mindful of the risks Bush brings, McCain has been aggressive about separating himself from the president. He has been laying out his own vision for the future with speeches on a slew of high-profile issues such as the U.S. posture in the world, climate change and the response to Hurricane Katrina.

During one such address Tuesday in Denver, McCain sought to contrast what he portrayed as a bipartisan vision on nuclear nonproliferation with that of Bush, who critics contend has engaged in partisan go-it-alone cowboy diplomacy that has strained U.S. relations across the globe.

In a way, even the White House is aiding in McCain's effort to chart his own course.

"President Bush isn't on the ticket," Dana Perino, the White House press secretary, said Tuesday in what has become a familiar refrain for characterizing Bush's campaigning on behalf of McCain. "At the end of the day, any candidate who's running for office has to stand on their own two feet. They have to chart a course for themselves. Every election is about change."

Still, a prideful White House has delicately tried to deal with McCain's not-so-subtle efforts to distance himself. When the president isn't by McCain's side, the White House offers lots of reasons: Bush is busy abroad, he's the commander in chief.

McCain has struggled to break from Bush on two key issues — the Iraq war and the economy. Both men support continued military involvement in Iraq, and they both seemingly back the same free-market economic principles. And that has given Democrats plenty to talk about.

To be sure, Bush seems aware that he could be a drag on McCain. In March, the president said: "If my showing up and endorsing him helps him — or if I'm against him and it helps him — either way, I want him to win."

Earlier this month, Bush seemed — by design or not — to assume the traditional lame-duck presidential role in trying to assist the GOP nominee-in-waiting.