Stars and politicians collided Saturday night at the annual White House Correspondents’ Association Dinner, as media-types mingled with their glitzy Hollywood guests during one of Washington’s most entertaining evenings. The celebrity-studded crowd dined in between laughs at speeches from the president and host, said Post reporter Dan Zak :

Hollywood and Washington went on a romantic date Saturday night in the basement ballroom of the Washington Hilton, where more than 2,000 politicians, celebrities, journalists and hangers-on dined on crabmeat terrine and chocolate truffles and belly-laughed at remarks delivered by President Obama and late-night host Jimmy Kimmel during the annual White House Correspondents’ Association dinner.

“Last year at this time — in fact, on this very weekend — we finally delivered justice to one of the world’s most notorious individuals,” Obama said during his after-dinner speech, seeming to allude to the killing of Osama bin Laden. But then a photo of an orange-faced Donald Trump — who spent much of last spring questioning Obama’s citizenship — flashed on giant screens in the ballroom. Punch line delivered.

Both Obama and Kimmel took their own shots at presumptive GOP presidential nominee Mitt Romney.

“It’s great to be here this evening in the vast, magnificent Hilton ballroom,” Obama said, “or what Mitt Romney would call ‘a little fixer-upper.’ ”

Said Kimmel: “When I think ‘Mitt Romney,’ I don’t think Etch a Sketch — I think of Twister. You can’t even play Monopoly with him, because he keeps putting the dog on the car .”

But the real sagas of the evening played out during the pre- and post- parties, as Washington power-players conversed with silver-screen royalty. George Clooney, who was arrested in Washington during his last visit a month ago, is a professional at effortlessly working the crowd, the Reliable Source reports :

We have so much to learn from George Clooney: As thousands of guests tried to bolt from the ballroom of the Washington Hilton at the end of the White House Correspondents’ Association dinner — in a mad rush for the after-parties or the taxi line — Clooney stayed at his table and poured another glass of wine.

It’s not easy to be a celebrity at one of these things, besieged from all sides by fans and distant acquaintances — no, really, that stuff is exhausting! — but the Oscar winner spent the entire dinner posing for photo after photo with every female who could squeeze into a frame with him.

And then he spent the next three hours on his feet — we watched, so we know — schmoozing a parade of VIP guests (Harvey Weinstein, Barbara Walters, Jay Carney) in the front foyer of the Bloomberg/Vanity Fair after party at the French ambassador’s residence, but making it all look like fun.

Clooney also found time to praise his former “ER” colleague, Noah Wyle. The actor had also been arrested for protesting in the District, a move Clooney supported, says Celebritology’s Jen Chaney :

“I saw it, when he got handcuffed,” said the Oscar-winning actor/director, who himself was arrested March 16 outside Washington’s Sudanese Embassy for protesting the hunger crisis in Sudan. That occurred a few weeks before Wyle’s April 23 arrest during a protest against Medicaid cuts.

“And I wrote him,” Clooney laughed. “I said, ‘Do you need bail money?’”

“He’s a good kid,” Clooney continued, referring to Wyle. “What, he’s a kid — he’s 40. He’s a good man and I’m happy to know him.”

When this reporter suggested that Clooney’s next mission should be to get Anthony Edwards, another “ER” co-star, arrested for protesting some important policy issue, he quipped, “We’ll get everybody arrested. Last time I was here [in Washington] I was in handcuffs.”

Diane Keaton, a seasoned vet like Clooney, played the part of flattered guest well, says Roxanne Roberts and Amy Argetsinger:

At the dinner, a 40-something guest cornered Keaton, resplendent in a white suit and tie and bowler, and started peppering her with lines from “Annie Hall.” (Including, in a respectable Woody Allen imitation, “Talk to him. You speak shellfish!”) Ugh, total amateur move, right? Reader, she loved it! Or at least put on a good show of laughing and clapping and smiling. The man turned to a bystander: “You’re my witness! She thought it was funny!!”

Actress Lindsey Lohan did not fair so well. After missing her intended flight Friday and arriving later than planned, the young actress seemed overwhelmed and panicked, Reliable Source reports :

Stipulated: What might be your way of having fun at one of these things might cause another person’s definition of torture. The price of Lindsay Lohan’s being the evening’s buzziest guest was the dark side of so many of these dinners: The mobs that pressed in around her dinner table, pointing and staring and analyzing from just a few feet away, like with a zoo animal. Her host, Greta Van Susteren, an experienced veteran of these dinners, seemed to be whispering some words of reassurance to the clearly unnerved starlet.

Matthew Morrison fielded questions from the Post’s Jen Chaney about working with Lohan recently on the set of ‘Glee.’ In a move of Washington-style diplomacy, Morrison gave a quick and conclusive answer, Chaney says :

When I asked Morrison whether he shot any scenes with Lohan, he said no: “I saw her on set, but I never worked with her.”

And have things gone okay with Lilo being part of the “Glee” mix?

A long pause from Morrison was followed by a laugh and a diplomatic response.

“I think it was all right,” he said. “The work got done.”

More on the dinner and surrounding parties:

Hollywood and Capitol Hill shine at correspondents’ dinner

Clooney at White House correspondents’ dinner , commenting on Noah Wyle arrest

Video: Jimmy Kimmel’s speech

Charlize Theron, Rashida Jones and more stars spotted at the Friday night pre-parties

President Obama’s White House Correspondents’ Dinner speech (Video)

The White House correspondents’ dinner as told in photos of Kim Kardashian, George Clooney and more

VIDEO: Highlights from the speeches

VIDEO: President, first lady enter the ballroom