Poor Marcus Dupree. He is 19 years old and sitting before a cadre of sportswriters from Chicago and New York, L.A., Washington and Philadelphia, all grown men with thinning hair and heavy, bruised pockets like thunderheads under their eyes.

These men left their homes and boarded jet planes in the middle of the night and flew to this dusty, brown town with hopes of discovering what it is like being Marcus Dupree. But now they look tired, weary. And it seems if Dupree poked their eyes he could certainly draw rain.

There were other writers and TV people here this morning, mostly locals, from Altus and Ada, Enid, Hollis and Holdenville, and they asked the questions he is being asked now, all the impossible questions he has brooded over since he first came to Norman to play football for the University of Oklahoma. Again, he is only 19 years old, a young expatriate of the South, new to college and big league football and a terrain as broad and vast as the talent his coach, Barry Switzer, believes will make him "as good as anybody who ever played the game."

If he weren't Marcus Dupree, the premier running back in college football and the preseason favorite to win the Heisman Trophy this year, he would be just another college kid beginning his sophomore year. A kid with soft, dark eyes and gold-capped teeth and hair dressed into a brushed-back shock of circuitous ringlets; one who wouldn't have to grapple with his hopes and faults and fears and lay them bare to tired men with pads and pencils and microphones.

But, because he is 6 feet 3, 228 pounds, runs a 4.4 40-yard dash and possesses the power to carry himself into the nation's end zones Saturday after Saturday, writers flock down here to shoot the breeze with him between classes. They sweeten their voices and ask him loaded questions about Philadelphia, Miss., his hometown, and about growing up in the South, as if it were some nightmare-land, a black boy's perdition: three civil rights workers were killed in Philadelphia in 1964, the year of Dupree's birth.

Does he have any sense of history in regard to racism, they ask, stuffing recorders the size of Camel packs into his face? And he tells them, "No. Not really . . . Every now and then I miss my hometown. I miss being around the people I been around all my life. There wasn't much crime there, you know . . ."

Against a tough Ohio State team last Saturday, in front of 75,008 fans at sold-out Owen Field and a national television audience, Dupree was mortal. His motor sputtered and died in a a game the Sooners lost, 24-14. Had they won, it would have been Switzer's 100th career victory, but Dupree, the key to the Sooners' offense, bruised his knee in the second quarter, after gaining only 30 yards on six carries, and didn't play the rest of the game.

The week before, against Stanford in the season opener, he gained 138 yards on 24 carries, a worthy debut for the tailback who showed such promise as a freshman that Switzer junked the traditional Oklahoma wishbone for the I-formation.

"At Stanford," Switzer says, "he looked like a big, fat boy trying to be a running back. But people were falling all over and diving here and there. You knew then just how fast he is."

If Stanford was disappointing, Ohio State was nothing short of disastrous. "To me," Dupree says, "a good game is 200 yards and a great game is between 300 and 500 . . . I figure if you can get four or five 70-yard runs a game you can get what you want."

He ran for 905 yards, averaging seven yards a carry, and scored 13 touchdowns in the regular season last year to become the first freshman to lead the Sooners in rushing. And in the Fiesta Bowl, he gained 239 yards against Arizona State, a performance Switzer thinks "could have set an NCAA rushing record that never would have been broken. But he wasn't physically in shape. When the opportunity presented itself, Marcus couldn't do it."

Last winter, Philadelphia threw a parade on a dawn-till-dusk stretch called "Marcus Dupree Day" and unveiled a billboard on the edge of town that reads, "Philadelphia, Mississippi, Home of Marcus Dupree." This, however, is not a rare phenomenon in the South or any place else in America for that matter, because for many of us, our own personal glory abides in the triumph of such young phenoms as Dupree.

When Dupree was a sixth-grader and his reputation as something extra-special had already spread across Philadelphia, Hal Reese, the superintendent of the city schools, called him into the school board office just to meet him. The next year, when he was in the seventh grade, Dupree was dunking basketballs in the junior high school gymnasium. And, as a ninth grader, running the 100-yard dash in 9.5 across the poor cinder tracks of the county, all the way to the Mississippi state track meet, where he lost to Calvin Smith, now a world-class sprinter.

Football fans are, on the most part, a vicarious bunch, occupying castles built by college kids such as Dupree, though the players themselves are oftentimes displaced people. "Now that I'm here (in Oklahoma) it's all right," Dupree says, "but a little worse than I thought it would be."

There lies the irony. We sit under bright skies, chewing celery sticks and nachos, sipping on our pewter whiskey flasks, and dream of running touchdowns in the shoes of a schoolboy. This may be our home--Norman, Okla., or any other college town--but it's not necessarily home for our heroes. "Everybody expects me to run 70 yards every time I get the ball," Dupree says. "I wish I could do that."

We forget he left a gentle life in a gentle town, left his mother, Cella Dupree Connors, and his little brother Reggie, a 10-year-old who was born with cerebral palsy and has already endured 10 operations. "Reggie motivates me to do my best," Dupree says.

But what we don't forget are the stories that Dupree will quit college football and turn pro the way Herschel Walker did last winter, if his mother needs the money to pay Reggie's medical bills. And there are those stories that quote Dupree bad-mouthing Switzer and Switzer bad-mouthing Dupree. First it was Switzer critcizing Dupree for beefing up to 240 pounds--"With it being so cold up in Norman," Dupree protests, "it's hard to keep my weight down"--then Dupree saying playing for the Sooners and Switzer was no fun.

Switzer blames the press. "You can extract from the mouths of babes anything you want. Marcus has been used by certain people, but he's learned his lesson and is sensitive to all that now," Switzer says.

In the old days, before Herschel, Brent and million-dollar TV contracts for televising college football, a star tailback made a point of playing the humble hero. He wore a letter jacket and a crew cut and would certainly never turn his back on Wonderful U. and venture into negotiations with a neophyte football league for millions of dollars. He was a servant of the university, a manacled peon of a sports public that admired him for his all-America humility and team play.

But Dupree seems to have grown bigger than all that. He has grown so large in our eyes that even Herschel Walker, who loved his coach, loved his team, loved the state of Georgia, appears diminished in comparison.

What is confounding about Dupree is that he seems quite aware of his enormous potential and, as a result, is unfettered and has no master. Not the University of Oklahoma. And by no means Barry Switzer. He even admits school is "okay for some people," but not so for him. If he turns pro, he has admitted repeatedly, he will not come back to earn his degree.

Since Walker's signing, Commissioner Chet Simmons has said repeatedly that the United States Football League is not interested in obtaining any more undergraduates. A pending suit by Arizona kicker Bob Boris, however, challenges the USFL's eligibility rule. If Boris wins that case, players such as Dupree would have the opportunity to forgo their remaining years in college and turn pro.

"If they (the USFL) offer Marcus four or five million dollars," Switzer says, "I'll tell him to take the money and run."

Dupree believes Walker was "wise" in signing for the financial security offered by the New Jersey Generals: "Herschel did everything he could do in college. He was on a team that won the national championship and he won the Heisman Trophy."

And adds, "I guess I kinda try to follow in his footsteps to a certain degree."

Dupree says he chose Oklahoma over Southern Mississippi, UCLA and Texas because he wanted to play for a national champion and he wanted to win the Heisman Trophy, "another award you put on your shelf to collect dust," but one he would certainly like to win. If he had stayed in Mississippi, he says, "I wouldn't have been on the cover of Sports Illustrated . . . The world would still know about me, but not that much."

"He has more equipment to work with than most," Switzer says. "He's not as fast as Herschel, but he's bigger than all of them. I don't think anybody at 18 had his running ability. If his motor tunes up to 100 mph, he can pass up a lot of folks, but he's got to get it running."

Oklahoma boasts of producing three Heisman Trophy winners--Billy Vessels in 1952, Steve Owens in 1969 and Billy Sims in 1978. All three trophies are lined across the top of a great cabinet to the left of Switzer's desk, just three more bronze works in a room with dozens--on coffee tables, under lamps, shoved against potted plants--immortalizing the performance of such athletes as Dupree who wore the cream and crimson.

But now, with Dupree hobbling about with a bad knee and Switzer looking at Saturday without the tailback for whom his offense is geared, Oklahoma's hopes of another Heisman and a national championship have been diffused, at least for now, and replaced with a simple hope for getting by Tulsa without its best player.