In March, a smiling Sen. John McCain, R-Ariz., walked side-by-side with President Bush into the White House Rose Garden to bask in the president's endorsement.
"I'm very honored and humbled to have the opportunity to receive the endorsement of the president of the United States, a man who I have great admiration, respect and affection (for)," McCain said.
The happy occasion ended with a handshake for photographers, then the two men who had clashed at times in their political careers, walked off together. That was the last time the two were seen together in public.
McCain and Bush will reunite tonight. The president will headline a fundraiser for the presumptive Republican presidential nominee in Phoenix. But this time, when they come together, it will be a very private affair.
This fundraiser was originally supposed to be an open event at the Phoenix Convention Center, but the McCain campaign asked that it be moved to a private location.
"You don't ever want to stand next to somebody who has horrible favorability ratings, because it hurts you," ABC News political contributor Matthew Dowd said. "Standing next to someone who has bad ratings, (and with whom) you are on the same team, Republican, hurts you. So, he's got to figure out how to make that break and how to move past that, because if he is perceived as running as another Republican in the line of Bush, he can't win an election this year."
Even without the photographic evidence, Sen. Barack Obama, D-Ill., used the event to tie McCain to Bush.
"Today, John McCain is having a different kind of meeting," Obama said at a town hall in Las Vegas. "He's holding a fundraiser with George Bush behind closed doors in Arizona. No cameras. No reporters. And we all know why. Sen. McCain doesn't want to be seen, hat-in-hand, with the president whose failed policies he promises to continue for another four years."
At every opportunity, the Democrats have been seeking to characterize McCain as "McSame" -- a virtual clone of the president, whose election would be equivalent to a third Bush term.
McCain has reason to be wary. The president's approval ratings have slumped to an all-time low. More than 80 percent of the respondents in an ABC News/Washington Post poll said the country was headed in the wrong direction.
This month, Democrats grabbed a third Republican House seat in a special election to fill a vacancy, an especially sobering jolt for Republicans. After the loss of a GOP-held seat in Mississippi, Rep. Tom Davis, R-Va., said Bush was "radioactive" to congressional Republicans.
"I don't think the president is necessarily radioactive [for McCain]," Dowd said. "The president is more like Kryptonite, where he takes away some of John McCain's independent strength. When he appears with McCain, he removes some of the mantle that allows McCain to appeal to moderates, and that's not a good thing for John McCain."
McCain has been distancing himself from the president for weeks, at first tentatively, and now, increasingly boldly.
Two weeks ago, he broke with him on climate change, advocating mandatory curbs on greenhouse gas emissions. Bush opposes mandatory controls.
"There is a long-standing, significant, deep, strong difference on this issue between myself and this administration," McCain said.
In New Orleans, McCain strongly criticized the Bush administration's response to Hurricane Katrina.
Using exceptionally harsh language to criticize a Republican president, he said, "Never again, never again will a disaster of this nature be handled in the terrible and disgraceful way it was handled."
Even on the Iraq War, of which McCain is an ardent supporter, he now makes a point of highlighting his past criticism of the president's handling of the war before the surge. For months, McCain condemned what he called the "Rumsfeld strategy" in Iraq. Now, he attributes what he calls a failed strategy to both the president and former Secretary of Defense Donald Rumsfeld.
A spokesman for the McCain campaign scoffed at Obama's comments about the Phoenix fundraiser as a "superficial" attack. But he added, "John McCain has had clear but respectful differences of opinion with the president."
For McCain, it's a delicate balance: separating himself from Bush to appeal to independents and moderates, but not so much that it alienates the Republican base that still has a favorable view of the president.