A local columnist described trainer John Campo this week as a blight on society, an opinion that is gaining some fashion among people who have followed the Fat Man's act through the Triple Crown campaign.

Yes, Campo is loud, unpolished, uneducated, crude, insensitive, insulting, impetuous, egotistical. Yes, he does upstage his horse and his jockey. But this is no act, nor is it irrelevant to Campo's handling of Pleasant Colony, who will be heavily favored to capture the Belmont Stakes Saturday.

His personality is part of his essence as a trainer. People compare Campo's conduct this spring with that of Bud Delp, Spectacular Bid's trainer, who matched his verbiage, superlatives and use of the first-person singular. But behind all his bluster, Delp is a judicious, cautious horseman.

Campo acts the way Campo talks. This has been both a blessing and a curse in his career as a trainer. "I really wanted to be somebody," Campo said, explaining how his career began. "I'm fat. I can't dress. Can you picture me as a big executive? No. I figure I couldn't make it anywhere but the track."

Campo's perception of his own shortcomings probably helped drive him to succeed. Even people who are not his admirers concede that he is one of the hardest-working men on the track. An owner once said that he works 18 hours a day and spends the other six thinking about it.

"When you decide to train horses," Campo said, "you give up all your life except your family." The self-absorption that annoys or alienates some people is the impetus behind his career.

Even though he didn't plan it, Campo acquired the perfect education for a horse trainer. He worked as an assistant to Eddie Neloy, when his stable dominated American racing as no stable has done since.

His association with champions like Buckpasser and Gun Bow taught him how to manage high-class racehorses. When he went out on his own, Campol was wheeling and dealing with cheaper claiming horses, learning how to deal with the whole range of equine infirmities.

In his second year of operation, 1970, Campo was the top race-winning trainer in New York. Over the next decade, he won 50 stakes races. "I can train a horse," Campo declares flatly.

Yet the exuberance and confidence that has helped bring Campo so much success has hurt him, too. He gets excited about his horses, pushes them as he pushes himself, asks too much of them too soon. There is no surer formula for ruining a horse.

Campo prides himself on his ability to train young horses, and he has developed several winners of major 2-year-old stakes: Jackknife, J. P. Brother. Just the Time, Protagonist, Taling Picture. Not one of them amounted to anything as a 3-year-old.

His handling of Protagonist, who was the champion 2-year-old of 1973, was a disgrace. The colt was a virtual basket case as a 3-year-old, but Campo kept pushing him toward the Kentucky Derby, running him and getting him trounced, until his career was terminated.

The next year, he had a late-developing 3-year-old named Media, who raced four times during the spring and showed immense promise, even though he had not yet won a stakes race. Campo injudiciously pushed him into the Kentucky Derby and the Preakness, and Media never amounted to much of anything.

Campo has trained only one top-class horse who has managed to sustain his form over a long period of time -- his first Triple Crown candidate, Jim French. Given such a durable, consistent animal, Campo trained him with typical Campo excess. The colt started his career in July of his 2-year-old season and had 24 races going into the Kentucky Derby.

Lately, Campo has been impressed by the way an unraced filly named Unexpected. Turn has been training in the mornings. "She can fly!" he exclaimed.

But instead of giving her the chance to develop gradually, he entered her in a stake here this week. She threw her jockey and ran off, necessitating a scratch. If her trainer's past performances are any guide, Unexpected Turn will win a stake or two this season and will never be heard from again.

If Campo had been training Pleasant Colony since he was a 2-year-old, the colt's career would probably have been different. Pleasant Colony may have been fortunate to have been trained initally by a relatively ungifted horseman, P. O. O'Donnell Lee, who raced him sparingly and probably undertrained him.

Pleasant Colony came into Campo's care fresh and physically sound only a few weeks before the Kentucky Derby. The trainer didn't have to exercise any patience and restraint; his job was to develop the animal's potential in a relatively short time, and to keep him in peak condition for a relatively short time. That is what Campo does best as a trainer, and on Saturday he should have a Triple Crown to prove it.