Midafternoon at the White House. Word has just hit the Press Room that the British destroyer Sheffield is gone—zapped in the stormy South Atlantic by an Argentine missile. The sudden image of fire and 40-foot waves, of tossing lifeboats in an icy midnight, seems especially jarring in the somnolent Press Room. Outside, under a warm May sun, the big yellow buckeye tree opposite deputy press secretary Larry Speakes' window rears in full bloom, buzzing with honeybees.

"Let's go," says Sam Donaldson, abuzz suddenly with a fierce spring energy of his own. "Find out if they know anything about it. You'd be surprised how often we have to tell them what's happening." He strides from the cramped, windowless ABC cubicle like a lover late for a red-hot date. In the bullpen area reserved for print journalists, reporters clot anxiously around the Reuters ticker.

"Rule Britannia!" bellows Sam in basso mock-profundo. "Britannia dum-dum-dee..." Heads snap around and glare exasperation. "That's for the benefit of Ralph Harris, the Reuters man," Sam explains. "Nearly everyone here is pulling for Britain in this half-ass war, or whatever it is. I'm trying to redress the balance by rooting for the Argies." He raises his voice: "Hey, Ralph! Sic semper tyrannis!"

Red tie flying over the shoulder of his trimly tailored shirt, Donaldson scoots past pretty secretaries and grim-faced Marine sentries, skids to a halt outside Speakes' office, peeks in with foxy menace, and exults: "Ahah! You're here. What does the President think of this Sheffield business?"

"He didn't say anything about it." Speakes looks up sleepily, plump and rumpled, from a desk littered with Tab cans.

"Does he even know about it?" Donaldson snaps, his blue eyes slanted in a vulpine leer. Speakes snorts, almost yawns, but doesn't bother to reply.

"Thank you," says Sam abruptly. "Goodbye." He spins on a neatly polished Bally heel and exits at racing speed. A short while later, lurking near the double glass doors that lead to the Rose Garden, Sam spots his real prey: Reagan, walking hurriedly amid a phalanx of Secret Service men. "What about the Sheffield?" Sam roars through the glass. ("You've got to yell loud," he apologizes. "The man is half deaf in one ear.") The President turns, raises his arms in a half-apologetic, half-fatalistic gesture, and flashes the famous Ron Reagan grin. "It's been reported," he hollers back. "I just hope for a peaceful settlement."

Donaldson dashes back to his cubicle and calls Frank Reynolds at the anchor desk in ABC's nearby Washington bureau. He tells Reynolds he's sensed a shift in the White House mood. Last weekend Reagan had come out strongly for Britain in the South Atlantic dispute. Now the President seems to be retrenching toward a desire for a negotiated settlement. It's not enough to warrant a spot for Donaldson on the ABC news that night, but Reynolds will use it in his own lead on the war.

"A big day on the White House beat," Donaldson sighs ironically. "The stuff of history. Who needs this? It's crap!" Then he glances up at the clock. "Almost 6 o'clock—time for the news," he says, excited again. "C'mon, let's listen to what Frank has to say."

"Crap" it might have been—on that slow newsday at least—but Samuel Andrew Donaldson Jr. had mined it with his customary aggressiveness. Big news or small potatoes, Sam Donaldson goes after it each day like an Argonaut. For more than five years now ABC's chief White House correspondent has alerted, informed, sometimes amused and often angered two Administrations and a growing audience of television news junkies with his pugnacious, high-decibel questions and acerbic, head-bobbing interpretations of the daily presidential rounds. Press corps colleagues, irked at Sam's irrepressible showboating, have described him variously as "obnoxious," "obdurate," "boorish," "contentious," "mercurial," "insecure," "petulant," "a clod" and "a belligerent ass."

Even his worst critics, though, admit that Sam Donaldson is a scrupulously accurate reporter. Tenacity and wit, honesty and a well-informed instinct for the jugular underpin his class-clown antics and superabundant amour pro-pre. As ABC News boss Roone Arledge, an unabashed Donaldson devotee, rightly points out: "More often than not, when the President says something newsworthy, it was Sam who asked the question."

Like the time in Cairo, in 1978, when Jimmy Carter was hammering together his hard-earned Middle Eastern peace settlement. "We were at the airport and Carter came out," Sam recalls. "I yelled at him, 'Is it peace yet, Mr. President?' He started to give us some wishy-washy stuff in that unwilling-to-commit way he had, so I yelled even louder: 'Yes or no, is it peace?' He widened his eyes a bit and stared at me. Then he yelled back, 'Yes, it's peace!' I'm damned proud of that."

As for the high jinks that have earned Sam his reputation as a cutup in a city that takes itself perhaps too seriously, Donaldson says it's all part of The Act. "You've got to be an exhibitionist to succeed in this business," he argues. "I've always been a show-off, always will be. I could go before the people right now and say I've always believed in the sanctity of the First Amendment, the people's right to know. But that's bullshit. I'm in broadcast journalism because I wanted to get close to the right people." He pauses to ogle a pretty young thing as she passes. "Much of the time, that means girls. To that end, I've been working on The Act all of my life."

For a while The Act had a lot of bite to it—literally. In 1977, shortly after taking over the White House beat, Sam attracted attention and no little criticism by chomping on ladies' forearms. "You know how some guys in pre-libber days would pat girls on the butt? I never did that kind of thing. But here, let me show you." He hikes into an anteroom near Speakes' office and approaches a shy, unsuspecting young blond secretary. "Isn't she just plain lovely?" he asks in his best Ted Baxter manner. "Such beautiful hands." He takes one, then suddenly growls like the Wolfman under a full moon and proceeds to munch the girl's forearm as if it were a cob of sweet corn. "I don't really use my teeth, of course—it's just a put-on. There you go, honey." He surrenders the limb back into the custody of its blushing owner. "Unfortunately, some people took it seriously, and I gave it up soon afterward. Change or die, that's the one great rule of life."

The Act has been changing one way or another for 48 years, ever since Sam's birth in El Paso, Texas, a short haul from the family cotton farm in nearby Chamberino, N.Mex. His father died of a heart attack before Sam was born, and he was raised by his mother, Chloe, and a brother 15 years older than he. "My brother died 14 years ago, but my mother is still alive and well at 88," he says. "She still lives alone on the farm, hauls water to her chicken house in milk pails. I had a water pipe installed for her, but she won't use it. She won't move in with anyone else, either, much as I plead with her. She's stubborn, like I was as a kid."

That stubbornness—"I was a bit of a bad-ass," he recalls with a glimmer of pride—got him sent to New Mexico Military Institute in Roswell rather than to a regular high school. "I hated it at first," he recalls. "As a 'rat'—first year—my room was always a punishable offense. But in my final years there I shaped up, became a good little soldier, even made sergeant. They had a punishment there that I'll never forget. Ever been whupped with a toothbrush? It's just springy and small-surfaced enough to really smart. Sometimes I threaten my lady friends with it." He grins wickedly, with wolfish amusement.

At Texas Western College in El Paso (now UTEP) and later at the University of Southern California, Donaldson majored in "telecommunications." Afterward, disc-jockey and news jobs in El Paso and at Dallas' KRLD-TV gave him enough confidence (despite the failure of a short-lived early marriage) to try for the big time in 1961. "I packed everything I owned in my old black Buick and headed for New York. But all I could get was a brief stint as a bit player in a Playhouse 90 show for $80 a week. Finally I landed a job at WTOP-TV, the CBS affiliate in Washington."

Initially a relief announcer and occasional deejay, he soon was on general assignment: politics, civil rights demonstrations, urban riots. By 1967, when ABC hired him, he was already working as a local anchorman. "I fell into the White House job almost by error," he says with a laugh. "In '72 the network assigned me to McGovern's campaign—a sure loser. And in '76 they gave me Carter when he wasn't even expected to get the nomination."

Typically, Sam rode the Carters mercilessly through the next four years—as he has the Reagans lately—pointing up any and all absurdities, contradictions or wheel spinning in their public or private utterances. "The people who surround a President—his aides and advisers, even his family—seem to think he's some kind of god," says Sam. "They think the press isn't quite high-class enough to ask him questions. To hell with that noise! I'll ask a President whatever seems pertinent, and I'll yell or jump or roll on the floor if I have to for an answer."

Not everyone, of course, appreciates such athleticism in pursuit of a story. "I get all kinds of hate mail," Donaldson admits cheerfully. "During the Carter days, a lot of it accused me of being some kind of fascist out to get poor Jimmeh. Today I'm a Commie-pinko-Antichrist looking to scalp Ron Reagan. Listen to this letter, unsigned of course, from Phoenix, Ariz.: 'YOU KNOW-NOTHING! How you hope we won't listen to Mr. Reagan! WELL, JUST WAIT AND SEE, YOU STINKING SON*OF*A*SLUT. You worthless liberal!'

"Actually, as far as my personal politics are concerned," says Sam, "I've never revealed them to anyone. When people ask, I say I've voted in every general election since 1956 and I've voted for more presidential losers than winners. It's fun to watch them trying to figure it out. It can work both ways. I'm not actually enrolled with any party right now, but as to the personalities of the two Presidents I've covered, I've got very definite ideas.

"Carter didn't really like people. He tried to be humorous and self-deprecating, but you could see his inwardness in that little rictus of his. I've often thought that he and Rosalynn were more a business partnership than a marriage. Both she and Miss Lillian are very strong women. It's strange that Billy turned out so different from his brother—a real, old-time good ol' boy. Dumb, yes, grabby, yes, but a guy who really likes people." Sam smiles and shakes his head, and for a moment you see his Southernness showing: He has one of those tight, dark, stony-eyed faces you spot in old photographs of the Confederate dead at places like Shiloh and Chickamauga—the Scots-Irish yeoman-farmers who made and then nearly unmade America.

"Ronald Reagan," Sam continues, "is at heart a pretty good guy. If you needed it, he'd come out here right now and give you the shirt off his back, literally. Of course, then he'd go back into the Oval Office in his undershirt and sign legislation putting your crippled old mother on the bread line. And he wouldn't see any contradiction in the two acts. Each would come from the heart. As for Nancy, I feel she's deep-down a sincere, good woman, a bit puzzled and indeed hurt by some of the questions she is asked by the press."

Although he doesn't show it, Donaldson has been wounded himself. His second marriage, to Billie Kay Butler, lasted 16 years and produced three children. (A son from the first marriage, young Sam, is now 25 and working toward a doctorate in psychology at Duquesne University.) It ended in divorce last year. "It was my fault largely," says Sam. "I was never there for birthdays, holidays, anniversaries, class plays, dances, graduations. I have less time than ever now I'm divorced. Usually I'm up at 6:30 and not back to bed until 1 a.m. Saturday is my only day off. My kids sometimes come over and I cook for them—enchiladas, chili and black beans. Apart from that, I play a little tennis, do a bit of bike riding on the tow paths, try to raise roses—not those gaudy floribundas, but hybrid tea roses. They're more blight-resistant. I used to read a lot of books—spy stuff, history—but now it's only papers and newsmagazines. Even though mine is a small apartment, what with all the housekeeping chores I sometimes start to feel like the Little Lady."

In addition to his daily routine at the White House, Donaldson regularly anchors ABC's Sunday evening news show and appears frequently on Night-line. He also has a spot on David Brinkley's This Week show, where he often goes one-on-one against conservative columnist George Will. Financially at least, his hard work is amply rewarded.

"I won't say what I'm making right now because I'm going to be negotiating soon for more," he says. "But it's a helluva lot more than I ever thought I'd earn. About the time I first moved onto the White House beat, Roone Arledge hired someone for twice what I was getting. I sent him a note saying I felt I deserved at least as much as that newcomer. Roone called up as soon as he got my note and agreed to the raise. It was only a matter of minutes. But truthfully, money's not why I'm in this game."

Being on top of the news, in contact with the critical events of our time, is Donaldson's main motivation. After five and a half years at the White House, he is clearly looking toward a new role, one that will allow him to broaden his range. An anchor slot would suit him nicely, he feels. But there are serious questions about the suitability of his style to the job.

"I'm not cute, like Tom Brokaw," he admits, "and I don't have the folksy, reassuring tone of a Cronkite. Actually, Dan Rather and I have a lot in common, stylistically. We're 'hot' in the McLuhan sense—no-nonsense, pretty much humorless on camera, strong on fact and data. That can be off-putting to an audience. Maybe the White House beat, with its heavy underlying seriousness, shapes a reporter in that direction. Even now, people see me doing a spot out there on the South Lawn and they say, 'There's Dan Rather.' And they're not needling me—they just expect to see him there."

Sam's self-criticism is underscored during an on-camera spot that very afternoon. It's late, pushing hard toward the 6 o'clock deadline, and he's doing a "thumbsucker" on renewed White House peace initiatives concerning the Falklands. He has his lines down pat for the first take, but lighting problems dictate a retake. Suddenly he's blowing every other line, getting angrier and angrier. "Okay," he says, gritting his teeth. "Take 3,001..." Finally he finishes, with no time to spare. "I've got to learn to take things cooler," he admits as he walks back to the Press Room. "When things go wrong, they just get worse for me. And of course it comes through on camera. Al the end there, I couldn't even remember my own name. 'This is Peter Rabbit, ABC News, at the White House.' "

Not—as Ralph the Reuters Man might say—bloody likely.