Updated

At a time when the Obama administration is reeling from a pair of high-profile scandals, the president paused Saturday night to thoroughly mock them before a crowd of dressed-up journalists and celebrities at the White House Correspondents Dinner.

Few topics were off limits as President Obama roasted his own administration officials, while reserving a stinging string of punch-lines for targets ranging from Mitt Romney to Newt Gingrich to Donald Trump.

His closing line poked fun at the Secret Service, which for weeks has been embroiled in a prostitution scandal after agents were found carousing with women in Colombia ahead of the president's visit.

"I had a lot more material prepared, but I have to get the Secret Service home in time for their new curfew," Obama said, referencing the agency's new rules of conduct.

The president also ripped the General Services Administration, over the agency's now infamous 2010 conference in Las Vegas.

More On This...

"I mean, look at this party.  We've got men in tuxes, women in gowns, fine wine, first-class entertainment," he said. "I was just relieved to learn this was not a GSA conference."

The dinner was far from a campaign-free zone. The president pointed out his similarities with the presumed Republican nominee, Mitt Romney.

"We both think of our wives as our better halves, and the American people agree to an insulting extent," the president said.

"We both have degrees from Harvard. I have one, he has two. What a snob."

The crack drew a thumbs up from former Pennsylvania Sen. Rick Santorum, who was in the audience. Santorum dropped out of the presidential primary campaign earlier this month. He had called Obama a snob for encouraging young Americans to attend college.

Obama also teased Newt Gingrich, who is expected to formally drop out of the Republican presidential race this coming week.

"Now, I know at this point many of you are expecting me to go after my likely opponent, Newt Gingrich," Obama said. "Newt, there's still time, man."

The president turned to make fun of recent stories about his childhood experience eating dog -- which he wrote about in his memoir.

"Even Sarah Palin is getting back into the game, guest hosting on The Today Show -- which reminds me of an old saying: What's the difference between a hockey mom and a pit bull?  A pit bull is delicious," Obama said, adding: "A little soy sauce."

He later joked: "My stepfather always told me, it's a boy-eat-dog world out there."

Even the entrance to his speech was part of his schtick. The president walked off stage just before he took the podium with an alleged "hot mic," making fun of getting caught last month on an open microphone with Russian President Dmitry Medvedev.

"What am I doing here," he asks off stage. "I'm opening for Jimmy Kimmel and telling knock-knock jokes to Kim Kardashian."

Once on stage, the president revisited last year's dinner, which took place as Navy SEALS were dispatched to capture and kill Usama bin Laden.

"Last year at this time, this very weekend, we finally delivered justice to one of the world's most notorious individuals," Obama said. Then a picture of real estate mogul Donald Trump appeared on the room's television monitors. The president last year delivered a scathing roast of Trump, who flirted with running for the Republican nomination and claimed he had solved the "mystery" of Obama's birth certificate.

Obama also took a shot at the Republican congressional leadership, whom he thanked "for taking time from their exhausting schedule of not passing any laws" to attend the dinner.

Four years ago, Obama recalled, he was locked in a tough primary fight with Hillary Rodham Clinton, now his secretary of state. "She can't stop drunk texting me from Cartagena," he said, referring to their recent trip to the Summit of the Americas in Colombia, where Clinton was photographed drinking a beer and dancing.

But Obama touched on serious themes as well, remembering The New York Times' Anthony Shadid and Marie Colvin of the Sunday Times of London who died while covering the uprising in Syria.

"Never forget that our country depends on you to help protect our freedom, our democracy and our way of life," Obama said.

Then he returned to the lighter side: "I have to get the Secret Service home in time for their new curfew."

Jimmy Kimmel, the night's featured entertainer, picked up on the Secret Service prostitution scandal in Colombia, saying he told the Secret Service that for $800 he wouldn't joke about them, "but they only offered 30."

"If this had happened on President Clinton's watch, you can damn well bet those Secret Service agents would have been disciplined with a very serious high five," Kimmel said.

Kimmel later asked Obama: "You remember when the country rallied around you in hopes of a better tomorrow? That was hilarious."

"There's a term for guys like President Obama," Kimmel said with a pause. "Probably not two terms."

Among the eclectic crowd attending Saturday night's dinner were former Secretary of State Colin Powell, the cast of the hit TV show "Modern Family," actress Lindsey Lohan, Army Chief of Staff Gen. Ray Odierno, House Majority Leader Eric Cantor, R-Va., actor George Clooney and director Steven Spielberg.

Proceeds from the dinner go toward scholarships for aspiring journalists and awards for distinction in the profession.

The association was formed in 1914 as a liaison between the press and the president. Every president since Calvin Coolidge has attended the dinner.

Several journalists were also honored at the dinner:

-- Matt Apuzzo, Adam Goldman, Eileen Sullivan and Chris Hawley of The Associated Press, for winning the Edgar A. Poe Award for their stories about the New York City Police Department's widespread surveillance of Muslims after the Sept. 11 terror attacks. It's the fourth major prize for the series, which has also won the Pulitzer Prize for Investigative Reporting, the Goldsmith Prize for Investigative Reporting and a George Polk Award.

-- ABC's Jake Tapper and Politico's Glenn Thrush, Carrie Budoff Brown, Manu Raju and John Bresnahan, for winning the Merriman Smith Award for excellence in presidential coverage under pressure. Tapper won in the broadcast category for breaking the news that rating agency Standard & Poor's was on the verge of downgrading the federal government's triple-A credit rating because of concerns over political gridlock in Washington. In the print category, Thrush, Budoff Brown, Raju and Bresnahan of Politico won for their report on the deal between Obama and congressional Republicans to raise the U.S. debt ceiling.

-- Scott Wilson, of The Washington Post, for winning the Aldo Beckman award. Wilson was recognized for his "deeply reported and nuanced stories, his evocative writing and his clear presentation of complex issues, particularly on the foreign policy front."

The Associated Press contributed to this report.