A report in Sunday's Metro section implied incorrectly that Operation Big Vote, a campaign to encourage blacks to register to vote, was affiliated with the Rainbow Coalition, an offshoot of Jesse L. Jackson's primary campaign organization. Operation Big Vote was a nonpartisan project sponsored by the National Coalition of Black Voter Participation.

When the elected Democratic officials in Prince George's County took the podium at the New Carrollton Ramada Inn last Tuesday night for a round of victory speeches, they were joined by Bennie Thayer, a Landover businessman who holds no elective office but who shared the election victory all the same.

Until earlier this year, Thayer, 44, was a virtual unknown in county political circles. But his presence alongside Rep. Steny Hoyer, County Executive Parris N. Glendening and a host of state legislators testified to the influence he and his "Rainbow Coalition" have gained in local politics.

The Rainbow Coalition, a local offshoot of Jesse L. Jackson's primary campaign organization, has evolved into a hardy band of political idealists statewide and locally who say that the excitement generated by the Jackson campaign should not be allowed to dissipate. Many of its members in Prince George's are not elected officials but hope to be.

Local political observers ranging from County Council members to Rainbow Coalition activists agree that increased black voter registration and turnout in Prince George's was the key to making the county one of only two Maryland jurisdictions that Democratic presidential nominee Walter F. Mondale won. The other jurisdiction was the traditionally Democratic city of Baltimore.

Precinct returns provided by the county Board of Elections Supervisors also support the Rainbow Coalition's argument that areas with a majority black population supported not only Mondale, but also the ballot question that sought to revise the county's strict tax revenue limitation measure known as TRIM.

All of this makes Thayer and Rainbow Coalition members in Maryland feel confident about the role they will be able to play in statewide elections in 1986.

A number of Rainbow Coalition members have already begun to float trial balloons about seeking elective office then. Among them:

* Thayer has said his target is Hoyer's seat in Congress, whether or not Hoyer chooses to run again.

* Wayne Curry, a well-known county zoning lawyer, who will not confirm his interest in a specific office. But others mention his name as a potential candidate for Hoyer's seat, for Charles McC. Mathias' U.S. Senate seat or Glendening's job.

* Albert Wynn, the 25th district delegate, has said he aspires to B.W. Mike Donovan's state Senate seat. In a district that has become 65 percent black by one estimate, Wynn thinks he can ride a new voter tide to victory.

* Alvin Thornton, a political science professor at Howard University, is mentioned by coalition members as a candidate for a variety of positions, including county executive.

* Alex Williams, a lawyer in the county, is touted by Thayer as a possible candidate for State's Attorney Arthur A. Marshall's job.

While these individual ambitions have yet to crystallize, it is clear that the elected and unelected politicians in Prince George's County have a sense of the power that this new breed of black politicians has begun to wield.

Thayer and other coalition associates virtually leaped into the leadership gap that was perceived to exist in the county's black political community when former state senator Tommie Broadwater, considered the dean of black politicians in Prince George's, was jailed this year for food stamp fraud.

"It's now becoming hardball," Thayer said after last week's election. "We're ready to start capitalizing on what can be done."

Royal Hart, a former state senator who is the county's legislative liaison and a moving force behind the successful campaign to amend TRIM (Tax Reform Initiative by Marylanders), also gave the Rainbow organization kudos.

"The Jackson campaign in the county activated a lot of new voters, and new voters are less likely to get bent out of shape over taxes," he said. "They're more concerned about good schools."

Glendening praised the Rainbow organization's success in attracting voters who supported Mondale and the TRIM modification, as well as the campaigns of two sitting judges, one of whom is black. State Sen. Leo Green, who has close ties to the traditional Prince George's Democratic leadership and who noted that the majority black precincts in his mostly white Bowie area district voted heavily, said that the Jackson voter residue has been good for the county.

"They certainly played a very positive role," Green said. "I think they want a greater piece of the action, and in those districts where they got the voters out, I think it's only fair."

But there is no uniform agreement on the Rainbow organization's power among the county's old-line Democrats. Gary Alexander, a state delegate who is chairman of the county's Democratic Central Committee, is not as eager to credit the Democratic success Tuesday to anything other than a joint grass-roots effort.

"I don't think the Rainbow Coalition was successful in the general election , because they were working within the Democratic Party," he said. "The Rainbow Coalition didn't ask for anything," said the 25th District's Donovan. "They sort of put demands on us. I look back to Tommie Broadwater, who I used to have a great deal of admiration for. He got his way by working within the party."

James Pringle, who coordinated Operation Big Vote as part of the Rainbow effort during the primary and general election campaigns, said that he and others like him are hoping to achieve representation on the local level that matches the county's 37 percent black population. "The mentality of the electorate has changed," Pringle said. "It has become as sophisticated as any jurisdiction in this political area, if not more."

One precinct in a community like Kettering, a racially mixed subdivision near the intersection of Largo Road and Central Avenue where Thayer lives, voted for Reagan in 1980 but supported Mondale this year. More than one-third of the residents who registered to vote in the area, District 13, Precinct 4, were new voters this year, according to returns, and nearly 600 more people voted in this year's general election than did in 1980.

In the Palmer Park precinct where the Rainbow Coalition has its headquarters, voter registration has nearly doubled since 1980, and more than 1,000 more people voted in the general election than voted there four years ago. In both precincts, Jackson won commanding victories in the May primary.

Wynn, who in seeking to unseat Donovan is taking aim at a politician with 12 years' background in the House of Delegates and five years' experience in the Senate, sees the Rainbow Coalition's expected gains as more issue oriented than personality oriented.

"Let's see what the guy is going to bring to the table," he said of politicians who he said have to seek Rainbow support. "If he's going to tap-dance and say 'I've always loved black people' or 'See what I've done for civil rights,' that won't work."

Instead, Wynn said, gubernatorial, congressional and local candidates in 1986 will be forced to prove what kind of concrete commitment they have to issues affecting the Rainbow's constituency.

"You've got to make sure there's a quid pro quo," Wynn said. "That when we support a candidate, that his policies . . . are consistent with our goals."

There is some evidence that the effort to bring out the black vote in Prince George's was not only effective, but that it also succeeded in shifting the tide in the Democrats' favor even more overwhelmingly than in 1980 when President Carter won the county by nearly 20,000 votes.

Even though the county's voter turnout, which was 74.2 percent in 1980, increased only slightly to 74.8 percent this year, the Democratic margin of victory more than doubled to more than 40,000 votes. In contrast, in Baltimore, Mondale outpolled Reagan 2 1/2 to 1, but by 15,000 votes fewer than Carter's winning total in 1980.

"The responsible thing for the white political establishment in Prince George's County to do is to recognize that this is a growing force that will not go away," said Steven Tillett, a program associate with the National Coalition on Black Voter Participation who is active in county politics.

Pringle, often credited with being the "nuts and bolts man" behind the Rainbow Coalition's effort, said that his group did precisely what it had to do for the general election in order to prove that the May primary victory was no fluke.

"The question of what we were going to do without Jesse, that question was answered," Pringle said. "Jesse gave us an idea and we took that idea and turned it into reality."