In the big league at Maryland's statehouse, where the pols play a rough-and-tumble version of political hardball, Montgomery County's delegation traditionally has been laughed at as the Baltimore Colts of the legislature--a nice group of boys, and some housewives, who really were not cut out for this sort of thing.

Contrast that image to, say, the down-and-dirty delegation from Baltimore City, the slick professionals who play the game tough with the single-minded purpose of increasing the city's share of the state's fiscal pie. For Montgomery, the General Assembly was more or less an extension of the garden club and the PTA as an outlet for civic activism. For Baltimore, Annapolis was the city's economic lifeline and a steppingstone for the politically ambitious.

Those are, of course, only stereotypes. But they are widely repeated if not totally believed. And the traditional labels--however exaggerated or unfair--can help one understand the mixture of astonishment and condescending smirks that greeted the Montgomery senators last week when they announced their plan to hold the proposed gasoline tax hostage while extracting concessions from Baltimore City.

The senators, in a letter to Gov. Harry Hughes, announced that they support a gasoline tax increase this year, but are dissatisfied with the decades-old formula for distributing the take. Under that formula, Baltimore City makes out like a bandit, getting half of the local allotment, while Montgomery receives the same percentage as Cecil County.

The senators never directly threatened to torpedo the gas tax. Outright threats could bring scorn and disdain from many of the well-heeled constituents back home, to whom such phrases as "vote trading" are still expletives deleted from the political lexicon. But then, the Soviets never really threatened outright to invade Poland either, but Warsaw got the message.

In talks with reporters--who didn't know quite what to make of Montgomery's new muscle-flexing-- the senators pointed out that they supported the gasoline tax last year as a unified block and that, without their votes this year, the tax would have no chance of passing.

"We don't want to kill the hostage," said Sen. Howard A. Denis. "We'll release the hostage unharmed. We'll ask for a small ransom."

The ransom they want is a change in the funding formula. But that's just their bargaining position for now. In the true spirit of negotiation, they have announced up front that they are willing to settle for less--it will do, they say, to use the current formula for now, if it is rigged to expire in two years. That will force Baltimore back to the negotiating table. As Montgomery Republican Sen. Edward Mason said: "The merit to the sunset is that it forces us to come back with a recommendation. It's a tool to keep the feet to the fire."

Baltimore lawmakers have said they would accept their version of a compromise--a year-long study of the distribution formula, starting next year. If the study group decides that the formula is unfairly weighted toward Baltimore, then the city's legislators will talk about negotiating a change. And if you believe that, maybe you'd be interested in buying some swampland in Anacostia.

Needless to say, some longtime statehouse pols were a little amused by Montgomery's threat.

"So Montgomery is pulling their thing," said Sen. Clarence Blount (D-Baltimore), chairman of the city's Senate delegation. "Oh well, this is an election year, so those are the kinds of shots we would expect."

The threat wasn't taken very seriously until the Monday night meeting of the task force voting on the gasoline tax. Del. Stewart Bainum (D-Montgomery) sure enough proposed sunsetting the distribution formula, and all of a sudden the Baltimore representatives stopped laughing long enough to realize that the Montgomery kids were throwing some rather hard pitches.

Del. Frank Robey (D-Baltimore) threatened to oppose other provisions in the package, like the one that says Baltimore's subway system should generate half its revenues from its ridership. Senate Majority Leader Rosalie Abrams, a Baltimore Democrat, observing the bloodletting, predicted, "If this spills out onto the floor, we're likely to have a schism." And a surprised House Speaker Benjamin L. Cardin of Baltimore said afterward: "I don't know what Montgomery County wants. Do you know what they want?"

"We used to have a bunch of white hats in our delegation," said Democratic Sen. Victor L. Crawford, the Montgomery County trial lawyer who heads the Senate delegation. "But we really started to change about five or six years ago. The reason we changed was that Prince George's, with Steny Hoyer as speaker, was really f------ us."

Asked if the county delegation would mind being labeled the assassins of the gas tax because of its horsetrading, Crawford replied, "Anyone who kills a tax increase in an election year is not an assassin. I wouldn't cry any tears if this thing went down."