Leave your corned beef on rye unchomped for 30 seconds and Jack is likely to pounce. Nothing sends him a message faster than a patron who takes too long between bites.

"A person looks like he doesn't like the sandwich, I throw it away and get hime another," says Jack Goldenson, 48, an exuberant Polish immigrant who has come to know the Power of Pastrami.

On a good day, the pot-bellied baron of Baltimore's Corned Beef Row dispenses 4,000 corned beef on rye to local cops, grimy dockworkers and spiffy lawyers in three-piece suits.They consider Jack's a kind of a kosher McDonald's and roam the street, from deli to deli, with the look of hungry wolves smacking the chops for their next lamb.

Jack's is the gastronomic gateway to Corned Beef Row, as the 1100 block of East Lombard Street is known, a huge, cafeteria-style delicatessan that hawks all manner of Jewish sould food: hot pastrami, corned beef on rye, hot kishka, spicy knishes and pickles as thick as Louisville sluggers.

Indeed, there seem to be more Jewish delicatessens in Baltimore than French resttaurants in Franch. And the seedy four blocks of East Lombard are considered the spiritual heart of Baltimore's Borscht Belt, a street that never lcaks for a crowd in search of the perfect corned beef on rye. Or a politicain in search of a vote.

It has been this way for almost as long as deli owners like Jack Goldenson can remember: the people coming for the sandwiches, the politicians coming for the people. "When they start out in politics, they all come down to our place, the mayors, the governors, the president's," he says.

At $1.79 for a lightly salted four-once heap of juicy, sufficiently fat brisket-corned and soaked in tubs of brine out back-the price is right chez Jack, the largest of the ethnic delicateness that line the road to corned-beef heaven.

For politicians, a visit to Jack's means plenty of greasy hands to pum and virtually guarantees a picture in the local papers. Over the years, they have learned to savor the karma of good corned beef, and, come election time, are quick to pay their respects to Corned Beef Row.

Jack's was bait enough for the late Hubert Humphrey. Jimmy Carter, on the campaign trail of 1975, chose to court the common man by ducking into Seymour Attman's Kibbitz Room, where the $1.85 corned beef sandwich tastes a tad saltier than Jack's. It also costs six cents more.

"So we charge a little more. But we cut it in half and serve it on a plate. We give personal service," says Attman, 52, a flamboyant self-promoter who took over the business from his late father, Harry. A diamond-studded gold wristwatch peeks from one cuff, a thick gold bracelet with Seymour abbreviated to "C-Mor" pokes from the other.

You had lunch?" he asks.

A corned beef on rye, a tangy hot pastrami, a swollen pickle and a cup of chicken noodle soup thick as a tar pit are summoned for the visitor. Enough, already. The visitor is stuffed. He has already eate at Jack's.

"Jack's!? snorts Seymour, a chunky grocer who finds it hard to resist his own cooking. "He runs a factory, a cold hub-bub. I run my place like Duke Zeibert's. You come here to get served well. Wouldn't you rather buy wool from Scotland than Korea?"

"He's just jealous because I'm the biggest - and the best," laughs Jack, who rebuilt and expanded his restaurant after the original was torched during the 1968 ritos.

Along Corned Beef Row, deli owners keep their knives sharp, ready to carve up the competition. They are shameless about honking their own horns.

"I was closed on Yom Kippur," says Perry Burstyn, 64, who owns Weiss' a small deli sandwiched between Jack's and Attman's. "But afterwards people said, 'Perry, I wish you'd been open. I had to eat next door and, frankly, it made me sick.'

"Of course, I am glad to hear this."

"Let me make you a sandwich," says Burstyn.

The visitor confesses he has just eaten next door.

"I was afraid of that."

A Menachem Begin look-a-like, Burstyn is a feisty, muscular little man who has written of his narrow escape from Nazi-occupied Poland. He has written of a time when German soldiers offered a bounty to his neighbors - a Jew's life was worth a bottle of vodka, or a kilo of sugar.

For almost a year, he hid in the woods, foraged in gardens for potatoes and carrots, begged for bread at back doors, slept in caves. "I lived like a rabbit," he says, crouching down and hoping about on his haunches to demonstrate how he made the forest his home.

It's all in the manuscript, handwritten in Yiddish and stained with pickle juice.

Such tales are dark threads that weave together thousands of Jewish merchants who once were jammed together in the squat, red-brick rowhouses of East Baltimore. They came here looking for a new life in ships that docked a few blocks from East Lombard, ships swollen with Poles, Lithuanians, Latvians, Germans, Italians. They saved their money and, later, sent for relatives, ofter survivors from the pogroms or the Holocaust.

East Lombard was on roadway to the melting pot, and the Jewish immigrants clogged the narrow street with produce stalls and pushcarts. They hawked vegetables and fruits and prayed and chanted together at dozens of neighborhood synagogues.

Today, only on Orthodox schul remains, as the street has given way to poor housing projects, cheap clothing shops, boarded-up storefronts and a liquor store that hawks pints of MD 20-20 and half-pints of harder stuff. The street has not yet recovered from the riots.

After a hard rain, if the wind is just right, the exhaust rumble of semis mingles with the smell of sweat, the stench from Yankelov's live chicken stall, the eye-watering fumes from Tulkoff's horseradish factory, the sweet donuts and cakes at Stone's Bakery and the spicy aroma of deli corned beef.

It's a strip of ethnic Americana, where one can buy champagne and caviar at the same counter as kosher hot dogs wrapped in bologna. The deli bins are stuffed with pickled onions the size of baseballs.

If a man is down on his luck, he can count on a free sandwich of scraps from Seymour or Jack, and a cheap suit or pair of shoes from Solomon Faiman, 86, and Orthodox Jew who immigrated from Kiev 50 years ago to escape the pogroms. For every purchase over $5, a customer gets a white handerchief.

First, though, one must persuade Faiman to unbolt the door, no easy matter. The gray-haired old man has been held up four times.

Carrol Watson, 89, a reed-thin black man, rattles the cage. He wants pants and long underwera. A regular. Faiman springs to life, darting between bins and shoe boxes. Out come khakis and longjohns. He tallies the bill on a paper bag. "Here you go, Pop. Thank you and stay well. See you later in the spring."

By the mid-1950s, merchants like Faiman moved away to nice homes in Pikesville, closing another chapter on the immigrants' tale. The rise and fall of East Lombard is as American as a corned beef on rye.

"All the big wheels used to live here," sighs Al Stein, 71, a clothier who leaned against a steel-caged storefront the other day and puffed on a corncob pipe.

Still, the lunch trade is steady. The city has plans for the area's renewal - more parking and the completion of "Freedom Park," a modern slab of granite on a patch of grass dedicated to the immigrants. And beat cops say the street is a safe place to visit.

BACKSTAGE at Attman's, a steam cloud hisses from a giant kettle of slowly cooking corned beef. In his kitchen office, a soiled blue smock over a coat and tie, Attman swivels back in his chair, fires up a fat Don Tomas cigar and nods toward Spiro Agnew. The former vice president smiles down from a photograph above the desk, next to the one of mourners at the Wailing Wall.

"Vice-President Agnew . . . escapes the voices of doom with bagels and lox in the Kibbitz Room . . ." proclaims a dining room wall parchment from the state comptroller.

The Kibbitz Room is Attman's holy of hollies, a kitschy dining arena of plastic chairs and tables where on chomps beneath pinups and politicians.

Some time ago, a minion requested that Agnew be exiled from his prominent hook, where he once hung beside autographed photos of Ted Kennedy, Jacob Javits, Tom Eagleton, William Proxmire, George McGovern, Henry Kissinger, J. Glenn Beall, Mac Mathias, Ted Venetoulis. Customers objected to eating in the same room with a man who'd pleaded noloto a felony.

Seymour says it pained him to evict an old friend from the Kibbitz Room, as it did when customers later asked him to relocate Marvin Mandel following the former Maryland governor's conviction on conspiracy charges. Recently, though, the courts reversed that one, and Mandel went right back up on the wall alongside the 75-pound Amberjack, a sultry calendar girl and other political fish.

"He was in over the Christmas holidays and gave us an order," says Seymour, proudly opening the books to Mandel's $87 payment. "He paid by check. He's always paid."

The phone rings. A local politician wants Attman to cater a party, cheap. "If I'm making 10 cents on you, I'm lucky," he moans. "You won't find a stauncher supporter in the area. You need any volunteers, I'll get you some help."

Seymor proudly unfolds a city hall check for $6,800 worth of corned beef sandwiches. Box lunches for city cops on snow duty.

"I love politics," says Attman, almost in a reverie. "I like the notoriety, the fanfare, mixing with people, knowing the judges . . ." He pauses, and, perhaps figuring this may not digest well in a post-Watergate profile, he adds, "But everything's on the up-and-up.Everyone's carful today. You can't go out of your way to help. Today's necessity was yesterday's luxury."

GOLDENSON says he cares little for local politics. Moshe Dayan is the only politician on his wall. Before the President's coup of shuttle diplomacy, Jack said he'd just as soon Carter stay put in the Kibbitz Room.

"Carter has no chutzpah ," shrugs Goldenson who, in 1941, lost his parents and five brothers and sisters to the Nazis in Poland.

He doesn't cater to anyone's nonkosher Mideast policy. "Russia Let My People Go," screams a banner of red paint in the free parking lot.

Jack was among 800 Polish war orphans shoehorned first into Russia, then into Iran and on into Pakistan. "No one wanted us," he says. The orphans huddled beneath tents in the desert until the British loaded them onto ships bound for Palestine. They were the first Jewish survivors to make it from Russia to Israel. Jack was 11.

At 16, he immigrated to New York, working summers as a waiter in the Catskills, winters in Miami Beach, where he met his first wife and moved to Baltimore, her hometown. He found work in a candy store, moved on to a grocery and lived a few blocks off East Lombard.

"I never felt anybody had to give me a thing. I always worked, had faith and positive thinking. I always believed there would be better day ahead. I was right."

He bought real estate, and, 15 years ago, opened Jack's an expanse of beige tile he claims is the "world's largest corned beef house."

"But no matter what you accomplish, when you look back, the past has left its mark."

Inside, they file past the "It's Good to Hire the Handicapped" poster of Moshe Dayan, the cigarette machines, the plastic Coca-Cola clock, through the turnstile and up to the counter. Cutting machines whine on automatic, shearing slabs of corned beef into slivers. Slap, onto the rye and into the foil. Sandwiches grow into stacks two feet tall. Pickled tomatoes, onions and pickles are plucked from barrels at the end of the line. Last year, three cash registers rang up $2 million in sales.

Most mornings, the CB crowd convenes to warm up their handles. Next come the cops, and, about 11, the shift workers. Sundays, it's the bagel-and-lox crowd and sports fans in season.

"Lombard Street has been good to me," says Jack. "I could have retired a long time ago, but feeding people makes me happy."

COME AND GET IT

To reach Corned Beef Row, take I-95 north into Baltimore, turn right onto East Pratt and drive half a mile past the Herald American building. Turn left on South Central, go one block and, for the best corned beef sandwich south of New York, take a sharp left onto Corned Beef Row. Park at Jack's (open daily, 8 to 6) and walk.

You're only five minutes by foot from other mouthfuls of history: The Constellation, the Flag House, McCormick's Spice Factory, the Science Museum, the Inner Harbor.

And if you're a night owl and decide to stay on, you may want to hook up with the Insomniac's Tour of Baltimore, which leaves the Maryland Science Center, at Baltimore's Inner Harbor, at 1:30 Saturday mornings. Tourists get to ride a 1900s open-air trolley, visit several homes on Stirling Street (the city's venture into $1 housing), watch the presses roll off the morning paper at the Baltimore Sun, catch a poetry reading at the grave of Edgar Allan Poe and hoist the flag as the sun rises over Fort McHenry. A gourmet breakfast at Cafe des Artistes is included in the $25 fee. For reservations, call Baltimore Rent-a-Tour at 301/653-2998. CAPTION: Picture 1, no caption; Picture 2, JACK GOLDENSON, OF CORNED BEEF ROW. By Bill Hensel.