It happened one night a few weeks ago in Glenarden. The town hall was stuffed with people, most of them black. They were all drawn to this political forum to find out why and how Decatur Trotter, the delegate and former mayor, was challenging his colleague, incrumbent Tommie Broadwater for the state senate seat in what is often referred to as "the black district" of Prince George's County.

Trotter answered the why and the how in a manner that few in the audience expected.

He charged that The Ebony Inn, a nightspot Broadwater operates on Sheriff Road, and a parking lot across the street were hangouts for drunks, aerlicts and dopepushers and had become "the number one menace in the 25th District." Then he criticized Broadwater, a bail bondsman, for bailing out "one of the most nortorious drug dealers in the area."

Trotter now says his attack was not meant to be personal and that he did not mean to imply that "Tommie was himself doing anything questionable." In fact, Trotter has refined his statements so much over the last week that now he claims only that he has "seen people selling alcohol in the parking lot on Sundays."

Broadwater, in reply, says that law enforcement agencies have been watching him closely since he came to power four years ago and have discovered that "I'm a guy who crosses every 't' and dots every 'i.'" Trotter's charge, he believes, was a "a smear attempt that backfired."

In any event, what was said that night at the town forum has reverberated through the 25th District - from Enterprise Estates to Seat Pleasant to Mount Ranier - in this, the most surprising and bitter Democratic primary contest in the county.

"Trotter surprised us all by going after Tommier like that," said one community activist from the black portion of Cheverly. "But it kind of reflected a split in the black community around here. Trotter is trying to represent the middle-class, well-educated high-brows who think that Broadwater is too much of a street person, too flamboyant with his bush and diamond rings and Cadillac. The race is about the business of class, image, style."

One image is of Tommie Broadwater wearing shades over his eyes and diamond rings on his fingers, making a living by bailing people out of jail and selling liquor and state lottery tickets, speaking softly and, as he says, "splitting my verbs"; worrying less about introducing legislation in Annapolis and more about making sure that the Democreatic leadership "gives my people a part of the pie."

The other image is of Decatur Trotter wearing the clothes of a bureaucrat; making a living as an administrator for a prisoner rehabilitation program: speaking eloquently and using words like "thus" and "therein"; worrrying less about the art of political compromise and more about concepts and dialogue.

"If you put Tommie and Trotter together into one person," sold a precinct captain," you'd have one belluva politician. One buy can do what the other guy can't.

For four years, since the Democreatic leadership belatedly carved out the 25th DIstrict to accomdodate the growing black population in the county (it is now said to be over 30 percent black), Broadwater and Trotter were, in a sense, together. They were elected on the same ticket and voted the same on almost every issue in Annapolis.

"We were a team," said Broadwater, referring to the district delegation of himself. Trotter and Dels. Francis Santangelo and Nathaniel Exum. "Every one of us had something different to offer, but we were working on the same things. I was shocked when Trotter decided to run against me."

"Then I got the knife in the back," said Broadwater. "he had to be crossing me all along."

Trotter says he was merely answering a "call from the people" when the decided to run against Broadwater. "The activists in the community just weren't happy with the way Tommie operated," he said in a recent interview. "He didn't respond to constituent needs, he couldn't think of things on his own."

As one example, Trotter said that at the start of the last session he came up with the idea of printing up a legislative newsletter. "The state pays for the printing, and it's good idea to let the constituents know what we're doing," said Trotter. "So I put the whole thing together and had it printed. Then Tommie saw it and noticed that my picture was on top of his on the front page. He went crazy and wouldn't let us sent it out. It was a petty thing."

Broadwater believes that he has been the subject of his share of petty things during the campaign. There was the night when nearly 100 of his yard signs were torn down in Palmer Pack. And the night he was arrested for trespassing in the parking lot of the Seat Pleasant Town Hall.

"I was just sitting there next to my car, chewing on a piece of chicken, when this guy came out and said I was trespassing and would have to leave," recalled Broadwater.

Broadwater and his supporters believe it is not a coincidence that the mayor of Seat Pleasant, Henry Arrington, is a Trotter supporter and that Arrington's wife, Evelyn, is running against his slate for a delegate seat. Arrington says there was nothing political about the complaint against Broadwater.

Arrington is one of several mayors in the district who are backing Trotter. Broadwater, however, is staunchly supported by County Executive Winfield M. Kelly Jr. and by the dominant political organization in the county. For the last four years, as Kelly has moved to give blacks about 20 percent of the jobs in county government, he has given Broadwater enormous power to decide who gets what job.

Broadwater has used this patronage power to cultvate a loyal constitnency in the 25th, but his relationship with Kelly has made some black leaders angry and jealous. "The party leaders pretend that Tommie is all-knowing and represents all the blacks in his district," Arrington complained in an interview several weeks ago. "It's a patronizing attitude."

Evelyn Arrington is considered by most district observes to be the strongest of the five delegate candidates challenging the organization state of Santangelo, Exum and Sylvania Woods Jr., a young Glenarden councilman who was tapped to replace Trotter.

The other candidates include Lillian Lewis, a community developer from Landover, Arthur H. Jackson, leader of the county NAACP youth division, Fred Price Jr., a social worker from Cheverly, and Maria Turner, a librarian from Mount Rainer.