Life always seems a mite stranger than fiction in the nation's capital, but when fiction moves eerily close to life, the results can be somewhat unsettling -- not to mention downright hilarious.

Picture a senile Ronald Reagan sitting around in his pj's on Jan. 20, 1989, refusing to move out of the White House or attend his Democratic successor's inauguration because it is simply too cold out.

Picture Christopher Buckley, former speech writer to George Bush and son of conservative columnist and Reagan intimate William F. Buckley, creating this irreverent account of the president's swan song in his new comic novel, "The White House Mess."

"I think after this book, my political nonfuture is assured," says young Buckley, though his blue-eyed, thoroughbred charm belies any concern he might profess about presenting the leader of the free world as out to lunch.

He was curious, he admits, "about what the reaction would be like over there . . . It's not a malicious opening scene, but it does have the president gone slightly dotty.

"The people I basically worried for were my folks, who are friends of the Reagans. Once my mother found out what it was about, she kind of had problems because she speaks to Mrs. Reagan fairly frequently. About a year ago, Mrs. Reagan asked her, 'Oh I hear he's written another book, what's it about?,' and my mom kind of rapidly changed the subject."

Of course, Christopher Buckley, 33, doesn't really have to worry about working in politics again, at least judging by the barrage of right-thinking politicos who stopped by his book party at the Hay-Adams the other night. A preppy presence in gray suit and pink tie, Buckley greeted White House Communications Director Pat Buchanan, former national security adviser Robert McFarlane, USIA Director Charles Wick, FBI Director William Webster and chief White House speechwriter Tony Dolan, among others.

Offered Dolan dramatically: "The book is a terrifying, thorough caution against the madness that power seems always to install in the psyche."

Buckley's parents have been close friends with the Reagans since 1964, when Ronald Reagan first entered politics. They often dine together in New York, and the Buckleys are frequent guests at state dinners.

"They're coming for the dinner with [Canadian Prime Minister Brian] Mulroney," says Buckley. "My mother said, 'We've also been invited to the 9:15 welcoming ceremony.' I said, 'Oh, you don't want to go to that, those are a bore.' She said, 'Well, I think under the present circumstances, I OUGHT TO!' "

Fortunately for everyone concerned, the bulk of Buckley's book, a clever satire of a White House memoir, is focused on the Democratic successor, Thomas Nelson Tucker, his actress wife, and the devoted aide who tells the tale. And if the Reagans were less than pleased by the way they've been portrayed, it wasn't evident in their gracious public response.

Nancy Reagan said through a spokesman that the book was "very amusing, well written and I enjoyed it."

"Mrs. Reagan said she had been with the Buckleys recently and they discussed their sons, the writers," said Elaine Crispen, the first lady's press secretary. "She read the book right after that."

Buckley says he also received word from the president. "I sent him a book, and he wrote back, 'I'm especially delighted to share in your new endeavor.' "

In addition to the Reagans, the book includes many other characters you've met before, either playing themselves or thinly disguised. Of course, if they're smart, most won't acknowledge their fictional incarnations.

The story is told through the eyes of Herb Wadlough, a wimpy former accountant who by some stroke of luck goes from balancing the new president's checkbooks to being the deputy chief of staff. In this capacity, he's the first lady's hand holder and marriage counselor, the baby sitter for the 6-year-old and basically the White House fusspot.

"Herb is a kind of Mike Deaver-type character," explains Buckley. "Not a substance guy but fancies he is . . . He's sort of balding, wears glasses that tend to fog up a bit and he's a little overweight . . . He drinks steaming hot water because he thinks it's good for his digestion. He's a schnook."

George Bush plays himself: Out of office in 1988, he makes a resounding comeback in 1992. "Sorry about unseating your guy," the vice president wrote Buckley recently, "but he was such a smarmy lap dog that he deserved it."

There's a press secretary named Mike Feeley, which sounds an awful lot like Pete Teeley, Bush's former press secretary. Feeley is a "pugnacious fellow of Irish descent," as Wadlough describes him, "with a florid complexion and unruly hair. (I often had to ask him to brush it before a press conference)." He has a foul mouth -- he's always calling something "a [expletive deleted] outrage" -- and is also a very enthusiastic media manipulator who looks at life as one big photo opportunity.

"It's outrageous," says Teeley, when asked to comment on his resemblance to Feeley. "It's a blatant attempt by Buckley to alter my previously known choirboy image. Beyond that, the only thing I can say is that my battery of attorneys is reading it and word is that Buckley is about to leave town." Getting in one last low blow, he calls the book "the most significant thing [Buckley's] written since he coined the term voodoo economics."

Maureen Dowd of The New York Times has a cameo role in which she gets the first lady to admit that she's going back into movies. ("I thought he should have developed my character more," says Dowd.)

And then there's the story about the girls brought in to keep the guys happy during the Tucker reelection effort. "I have never been on a campaign," says Buckley, but "I heard stories about the '80 campaign that gave me -- you might say -- some inspiration."

Buckley says he first came up with the idea of doing the novel after he left Bush's staff in February 1983. He had promised the vice president, he says, that he would never write a real memoir.

"When I went down to my interview with Bush, it was me and the vice president and everything seemed to be okay and Bush's and my hands were in midair to shake on it, when Teeley chimed in," Buckley remembers. "He said, 'Mr. Vice President, wasn't there something you wanted to ask Chris, you know, about NOT WRITING ANYTHING ABOUT HIS EXPERIENCES HERE.'

"But then after a year and a half, I had all this stuff, and thought what to do with it. I read a lot of White House memoirs and they all struck me as kind of chimerically scurrilous. They all have two themes. The first is, 'It isn't my fault,' and the second is, 'It would have been much worse if I hadn't been there.' So all the classic light bulbs went off and I thought, 'I'll write a parody of a White House memoir.' "

Buckley currently earns his living free-lancing and is an editor at large for Esquire. In 1982 he published "Steaming to Bamboola," an account of his 76 days on a freighter after graduating from Yale.

"The White House Mess" was rejected by five publishers, the author says, because the first draft was "a joke that went on a little too long." He doesn't want anyone to take the work too seriously (how can you?), but notes that there is indeed a message:

"If the book works, it should strike shame into the hearts of future memoirists. But you watch. It won't."