The installation of Roy Dabney, a black bank executive and former Chamber of Commerce president, as a Prince George's County Council member yesterday marked the quick rise of a political innocent to one of the county's coveted political spots through the unified efforts of Prince George's increasingly powerful black community.

Dabney, a community activist who had little experience with the county's political life, drew the strong backing of black community leaders, the council's two minority members and elected officials who represent Prince George's predominantly black district.

It was through the efforts of these groups -- who mounted what resembled a minicampaign that lacked only political buttons and literature drops -- that the 37-year-old Bowie resident was able to edge out two other finalists to take over a seat on the 11-member council recently vacated by Francis B. Francois. In the end, the political unknown, who received a quick education in politics provided in large measure by State Sen. Tommie Broadwater and council member Deborah Marshall, was brought onto the council yesterday by a unanimous vote of the 10 sitting council members.

That vote followed a six-hour closed session of the council late Monday night at La Scala restaurant in Suitland where the council, after heated debate, agreed on Dabney as a compromise candidate.

Dabney's success story began late in June after Francois, an at-large council member from the Bowie area, announced he would be retiring on Sept. 5. Because Francois was a Democrat, that party had the right to select his replacement.

Within a few days of Francois' announcement a speculative story appeared in one of the daily newspapers that mentioned Dabney's name as a possible replacement -- he met the major qualifications of residing in Bowie as Francois does and of being a Democrat. The problems with his candidacy were his reelectability from the predominantly white Bowie area in 1982 and his lack of political experience. No one is quite sure who first mentioned Dabney's name to the newspapers, but Dabney himself confesses that until that happened he had absolutely no thoughts of seeking the post.

"Until that time," he said recently, "it never crossed my mind."

Dabney officially put his name in for the part-time post, along with about 25 other hopefuls, after getting approval from his employers at First American Bank. It was only after this that he contacted Broadwater, Marshall and other black powerbrokers in the county. Unbeknownst to Dabney, activists in the black community, including members of the NAACP, had already begun pushing his candidacy. However, when Broadwater and the two black council members joined in, the fight for Dabney began in earnest.

"Tommy's thing is producing for his community," said one county politician, who asked not to be named. "He and Dabney hardly knew each other but Dabney was the only serious black candidate out there."

The first hurdle was getting Dabney's name through the Democratic Central Committee, a formerly powerless rubber-stamp for party leaders that gained new power and independence after 1978 when the Democrats' top leaders were defeated in elections. That turned out to be a relatively easy task, accomplished with telephone calls to central committee members with the committee members from Broadwater's 25th district strongly supporting Dabney.

Dabney made it through that round along with five others, including John Lally, a former aide to county executive Winfield M. Kelly, Democratic activist Mickey DeVaney and former Bowie mayor William Wildman.

It was from this list that the party leadership, newly reorganized into a decision-making group, was to select three or four names that would be taken once more to the central committee for an approval of three finalists. At this point, Broadwater's standing among the party's elected officials and his clout as the most senior black elected official came into play for Dabney. h

"I made it clear [to the leadership group] that if we [blacks] were going to be part of the Democratic Party then we deserved to be part of the three [finalists] sent to the central committee," Broadwater said yesterday, "We had a qualified candidate who met all the qualifications and we were owed participation. Basically, they agreed that a black should be that, and the black was Roy."

Broadwater's logic prevailed. The party's leaders endorsed Dabney and DaVaney and told the central committee to choose between Wildman and Lally for the third finalist. It would be up to the council then to select Francois's one replacement.

Broadwater, Marshall and other black community activists then mounted a full-fledged campaign to convince central committee members to vote for Dabney, DaVaney and Lally. Lally and his main supporter, council member Gerard McDonough, mounted a similar campaign, as did Wildman. It was these three who made it into the final list that was sent last week to the council.

After the central committee made its choices, the election strategy shifted to the 10 council members. An initial appraisal by all sides indicated that Wildman had the greatest number of votes -- the four conservative members of the council.

"It was an election with a 10-member electorate," said Lally supporter McDonough. "I must have made hundreds of calls," Lally said recently. Said Broadwater: "I told Roy, you touch base with everybody who ever made decisions in Prince George's County."

Both the Lally forces and the Dabney forces had the same strategy: defeat Wildman, who both sides believed was too conservative, and attempt to win away some of his votes. "Our strategy was to talk positive about our candidate and if people wanted to talk negative about other candidates we would," said Broadwater.

In the rumor-filled world of Prince George's politics, Dabney had one distinct advantage over Wildman and Lally -- his political innocence had left him without enemies.

By the end of last week, several council members had received telephone messages saying "Do not be for Lally: he's arrogant and insensitive." Others heard that Wildman was too much of a "single shooter," who would not stick by the council majority and had run against the party's slate in the 1978 primary.

Under such pressure, it became clear that Wildman, previously the front runner, would not be able to win the six-vote majority necessary for selection and the race narrowed to two traditional allies -- Dabney's backers and those for Lally. As Dabney pulled on his connections in the business community and his backers pressed for another black on the council, and Lally turned to supporters made in years of political activism, the fight became more than the candidates and centered around questions of party leadership, loyalties, philosophy and style.

It also became somewhat more bitter as the two traditional allies clashed over the one $24,000 seat. One final effort was made to work out a compromise to avoid that clash when long-time Democratic Party strategist Peter F. O'Malley convinced the two sides to meet for lunch at Broadwater's Ebony Inn and settle their differences. Broadwater, McDonough, Council Chairman Parris Glendening and state Del. Timothy Maloney discussed the council seat at the meeting but no compromise was reached and the two sides went into the council's closed door meeting at La Scala intent on winning the council post for their respective candidates.

After 13 rounds of straw votes, with no candidate able to win a six-vote majority, the council turned to Dabney as a consensus candidate who had alienated neither side. Said McDonough as he emerged from the meeting "everyone fought a hell of a fight [for their respective candidates]. Everyone walked a mile. But Dabney was a man for all seasons. He fit all the cards. The only thing he lacked was political credentials."