It's Barack Obama's house now, but his predecessor and political foil, George W. Bush, stole the show at the White House on Thursday with his wisecracks and grin.

"Thank you so much for inviting our rowdy friends to my hanging," the former president said, referring to members of his family and former staff, invited back to the executive mansion for the unveiling of his and Laura Bush's official portraits. "Behave yourselves," he jokingly admonished his crowd.

Bush told the current president he was pleased to know "that when you are wandering these halls as you wrestle with tough decisions, you will now be able to gaze at this portrait and ask, `What would George do?'"

Free from the stress of the presidency and after three years spent largely out of the spotlight, a relaxed and jovial Bush came back with his father, former President George H.W. Bush, for a rare gathering of three commanders in chief. Former first lady Barbara Bush was there, too, as were George W. and Laura's daughters, Jenna and Barbara.

While Bush, Obama and their wives spoke about the warmth between their families, there was little of that on display between the two presidents. They traded handshakes but no hugs. There was little casual small talk as they entered and exited the East Room or as they stood on stage together.

"We may have our differences politically, but the presidency transcends those differences," Obama said.

That the relationship between Obama and Bush is cordial but not close is hardly a surprise.

Obama is still bad-mouthing Bush's time in office, blaming him for the economic crisis, the soaring federal debt and the unfinished wars the Democrat inherited from his Republican predecessor. And in the midst of an election season, Obama is trying to lump the economic policies of his current Republican rival, Mitt Romney, in with Bush's.

Standing side by side in the grand, chandeliered East Room, Obama was mostly formal and subdued while Bush was light-hearted and engaging, relishing in the warm greetings from veterans of his two terms in office.

Bush said he was pleased that the White House portrait collection now starts and ends with a "George W." Noting that George Washington's portrait was famously saved by first lady Dolley Madison when the British burned the White House in 1814, Bush pointed to his own portrait and told Michelle Obama that "if anything happens, there's your man."

With a smile, the first lady assured him in her own remarks, "I promise, I'm going straight for" it in case of emergency.

The former president turned emotional as he spoke of his own portrait hanging near his father's _ "number 41" as he called him. On the verge of tears, the younger Bush thanked his father, who attended the ceremony in a wheelchair, for "the greatest gift possible, unconditional love."

More than any other president in recent memory, Bush has not just intentionally faded from the public spotlight but all but disappeared from it. He wrote his own remarks for Thursday's event, as he no longer employs a speechwriter.

It was just one week ago that Obama, revving up campaign donors, turned Bush into a punch line. Obama depicted Romney as a peddler of bad economic ideas, helping the rich at the expense of the middle class. He then added: "That was tried, remember? The last guy did all this."

The president steered clear of the political jabs Thursday, but didn't shy away from the economic crisis that began under Bush and has consumed Obama's term. Without laying blame for the recession, Obama said that after his election, Bush understood "that rescuing our economy was not just a Democratic or a Republican issue; it was an American priority."

Obama also recalled one of the most memorable moments of Bush's presidency from the days following the Sept. 11 attacks: "All of us will always remember the image of President Bush standing on that pile of rubble, bullhorn in hand, conveying extraordinary strength and resolve to the American people but also representing the strength and resolve of the American people."

Turning light-hearted himself, Obama also told Bush, "You left me a really good TV sports package. ... I use it."

Thursday's gathering of Bush-era aides had the feel of a college reunion. Before the presidents arrived, former staffers waved to each other and swapped stories. Even former White House reporters who covered the Bush administration came back for the event, crowding into the corners of the East Room.

While the few Democrats in attendance were far outnumbered by Republicans, the political tensions ran so low that even Vice President Joe Biden offered a hearty handshake and greeting to Rove, Bush's longtime political adviser and a foe of countless Democrats.

"There he is!" Biden exclaimed as he turned over his shoulder to greet Rove who was seated a row behind.

Obama personally greeted the Bush family Thursday afternoon upon their arrival at the White House. The Obamas then hosted a private lunch for more than a dozen members of the Bush family in the Red Room.

Current presidents hosting their predecessors for portrait unveilings is a long-standing political tradition at the White House. Bush held a similar ceremony for his predecessor Bill Clinton, who did the same for the elder Bush.

Artist John Howard Sanden painted the portraits of George and Laura Bush. The former president's portrait depicts him in the Oval Office in front of one of his favorite paintings, "A Charge to Keep." Laura Bush's portrait shows her in the Green Room wearing a long gown.

The former president's painting will hang prominently in the formal entrance hall to the White House, the Grand Foyer, a location Bush approved of.

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Associated Press writer Ben Feller contributed to this report.

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Follow Julie Pace at http://twitter.com/jpaceDC.