"Grandstanding?" drawls the self-styled country congressman. "You mean like, open the can of chili, the hot dog has arrived? . . .

"If I'm a grandstander," adds The Man Who Shot Gramm-Rudman, "then what the hell is Phil Gramm? A friend of mine told me the most dangerous spot to be in Washington is between a camera and Phil Gramm!"

Today, Oklahoma Democrat Mike Synar will have his hour in Washington's political sun, when the Supreme Court hears oral arguments on Bowsher v. Synar, the controversial constitutional challenge to the Gramm-Rudman-Hollings deficit reduction act.

The lawsuit -- which claims that automatic budget cuts mandated by the bill violate the constitutional doctrine of separation of powers, and which Synar initially filed alone -- certainly hasn't made him Mr. Popularity back home. After all, how can you be against a balanced budget in these deficit-bedeviled times? Synar was the only one of the eight Oklahoma legislators to vote against the bill itself.

The suit has also been something of an annoyance to his congressional colleagues, who have opted to jump on the deficit reduction bandwagon en masse. "A minor inconvenience," sniffs an aide to Sen. Gramm (R-Tex.), a primary architect of the legislation. But it has garnered lots of headlines for the relatively little-known Synar -- as well as added considerably to his hate mail.

"Thousands of letters," he says, explaining that a few of the conservative folks in Muskogee, Okla., have been displeased with him about some other things, too -- namely his stands for gun control and against contra aide.

"One day I got into the office early and answered the phone. A man said, 'Tell that SOB he's a jackass.' I said, 'Beg your pardon?' He said, 'Tell that SOB he's a jackass,' and then he said, 'How do I know you'll tell him?' I said, 'Sir, you're talking to that jackass.' Click."

Still, the 35-year-old congressman -- described by colleagues as irreverent and outspoken, a firecracker always ready to pop -- is undaunted. He says he'll sit in his reserved front-row seat at the Supreme Court this morning. And amid the quiet dignity of the mahogany and red velvet, he'll wear what he calls his good-luck tie.

"I'm known for my loud ties," he explains, riding the Capitol subway one day last week. "This one is green, with blue spots. Neon green. Oh, they won't miss me . . . "

Open that can of chili -- perhaps the hot dog has arrived.

Synar is an '80s Democrat, with a seeming aversion to old-time back-room politics and an instinctive understanding of what plays on the evening news. "Is that a sin?" he asks.

"We're about 15 years apart agewise, but about 25 apart in politics -- if you know what I mean," says mainstream Democratic lobbyist J.D. Williams, who learned the political trade as an aide to renowned former Senate kingpin Robert Kerr (D-Okla.).

Being a congressman is the only job Synar has wanted since he was 14, and he's devoted to it. "He's a prodigious legislator," says his friend Rep. Richard Gephardt (D-Mo.). "He likes to get things done."

Synar is a handsome, single man who fancies himself just a plain ol' country boy. On one recent day, though, the only sign of his ranch background was on his feet -- a pair of calfskin cowboy boots. He also wore a meticulously tailored taupe suit with maroon suspenders that nicely matched his maroon watchband.

He's just purchased a house on the Hill, which he says he decorated himself. "I spent three days walking around the Design Center. I told my mother my house looks like Ralph Lauren married Laura Ashley and moved in . . ."

Hesw,-3 tends to say things like "I love this country" and "If I could be Thomas Jefferson . . ." and "My favorite movie is 'Mr. Smith goes to Washington' " -- sentiments that can be a little hard to swallow in a cynical town like this.

Butsw,-2 his friends say the sentiments have real roots.

The son of well-to-do ranchers in rural Oklahoma, Synar joins hands with his family in prayer before dinner. When he was growing up, the 4-H club was one of his primary extracurricular activities. When he was 7 years old, his father took him down to the bank to borrow $7,000 to buy a herd of cattle -- a herd that would later pay for his education.

"We borrowed the note and bought 10 head of cattle and we reproduced those herds until I started college," says Synar. "We'd sell off a steer every time tuition came up. You knew you were ready to finish school when you ran down to the last cow. I ran out by the last year of law school."

*After graduating from the University of Oklahoma, and before starting law school there, Synar spent a year studying economics at the University of Edinburgh in Scotland and two years obtaining a master's in business from Northwestern University. "My father tells me I'm the most overeducated dirt farmer there is," he says.

In 1978, the year after he finished law school, he ran for Congress as a maverick with little institutional support. Using money borrowed against a portion of the family's 10,000-acre ranch, he defeated a weak incumbent in a close race.

More often than not, Synar is the lone dissenter in a moderate-to-conservative Oklahoma delegation. He refuses to take political action committee money, and has sponsored legislation that would limit to $75,000 the amount of money a House candidate could receive from PACs in any given campaign.

He showed a knack for PR right from the start. Shortly after he arrived in the House, he and Geraldine Ferraro, then a congresswoman from Queens, each made a high-profile visit to the other's district. The story played from Long Island to Tulsa, as she rode horses and he visited Broadway for the first time.

And as luck would have it, The New York Times, looking to chronicle a congressman's career from the day he arrived in Washington, settled on Synar's.

"That's an interesting story," he offers. "They had picked someone else, and the reporter was on an airplane and a friend of mine said, 'No, no, no, you've got the wrong guy. This guy is from Muskogee and he's the real Mr. Smith."

On why he's so fond of Frank Capra's schmaltzy film, Synar says: "I don't want to sound hokey, but . . . there's a reason. There's a line in there when he says, 'The only causes worth fighting for are the lost causes.' Opposing Gramm-Rudman-Hollings was one of those lost causes that someone had to fight, and I believe that."

The suit clearly has some merit, or it would never have reached the high court (a federal judiciary panel ruled in February that the mandatory budget cuts were indeed unconstitutional, because Gramm-Rudman-Hollings gives too much power to the comptroller general). Yet the grandstanding charge doesn't seem to go away.

Counters Christopher Matthews, spokesman for House Speaker Tip O'Neill: "At the time he took position to challenge the bill, the consensus was to roll with it . . . It takes a lot of nerve to take on an issue when everyone is jumping on the train."

Synar, too, disputes the suggestion that he merely capitalized on an opportunity for visibility.

"From the time I filed the suit in December until recently, I took a beating at home," he says. "Why would I hot-dog an issue that is a marginal political issue back home? It's been a tough few months."

He had questioned Gramm-Rudman's constitutionality from the beginning, but his lead role in the suit came more by accident than by design. A member of the Judiciary Committee, he was asked to join the House-Senate conference on the legislation because he was known to be opposed to it.

When it came time to file, Synar went to Alan Morrison, a well-known public interest lawyer, and asked how he should proceed. Morrison advised him to drum up another Democrat and two Republicans. According to Synar, he did so, but the other three opted not to file a day before the suit was due. Reportedly, the other three were Sen. Gary Hart (D-Colo.), Sen. Lowell Weicker (R-Conn.) and Rep. Silvio Conte (R-Mass.); Conte and 10 other House members ended up joining the suit three days after it was filed.

Synar says he gets along fine with Sen. Warren Rudman and Sen. Fritz Hollings (Rudman calls him "very dedicated, very intense and exceptionally bright"). But he has a definite problem with Gramm.

"He's not too happy with me," says Synar, explaining that he was quoted making some critical remarks about Gramm recently. "I said, 'He's a liar . . . He can't be trusted. He'd like to be king.' He and I do not have what you'd call a working relationship. We came in together in '78, and basically his word is no good. What happens is we're so polite around here . . .

"We play by one set of rules and he plays by another," Synar adds. "He's the worst user of people I have ever seen."

Synar won't speculate on where his career is heading, but it's no secret that he'd like to move on to the Senate. Some political observers believe that if Rep. Jim Jones (D-Okla.) decides not to run for the seat now held by Republican Don Nickles, Synar will be first in line with his petitions.

For now, he'll only say that he always wanted to be a lawyer by the time he was 25 and a congressman by the time he was 45, so he's way ahead of schedule.

But "I'm not taking myself out of anything," he says.