It seemed a sure thing in June 1977 that Wyatt Durrette, a popular General Assembly delegate from Fairfax County, would win the Republican nomination for Virginia attorney general.

Durrette packed an extra suitcase and was all set to hit the campaign trail after the GOP convention in Roanoke.

It wasn't to be J. Marshall Coleman, Durrette's only opponent, pulled off a convention upset that put him on the ticket headed by John N. Dalton and launched his political career to within striking distance of the governorship.

Today, Durrette, 42, again has his eye on the attorney general nomination. Once again he seems to have the nomination sewn up, only this time the convention is still a year away.

"They tell me it's the easiest way to win an election," Durrette, who has no GOP rival for the post in sight, said yesterday.

An attorney who lives in Vienna, Durrette laughs about his narrow convention loss now and candidly concedes that Coleman -- who went on to be elected attorney general that fall -- just plain outhustled him for the nomination.

"Going into the convention I had a 50 to 100 vote lead," he says. "Since I was perceived to be the winner, my supporters spent their time working for their favorite lieutenant governor candidates."

Durrette, who served six years in the House of Delegates and did not seek re-election when he decided to go after the statewide post, has had three years to learn from his mistakes and to campaign.

"Wyatt has made it a point to travel around the state at his own expense, making speeches, serving on panels, doing anything to maintain public contact," says State Sen. Wiley F. Mitchell Jr., an Alexandria Republican.

Adopting the same kind of early campaign aggressiveness that worked so well for Coleman, Durrette has been leaving nothing to chance. He visited Mitchell during the last assembly session to make sure the Alexandrian wasn't planning his own attorney general race. He's been "working the Main Street crowd" in Richmond for financial backing, according to a former legislative colleague, and has made his peace with the conservatives in the party who backed his rival four years ago.

"He's worked on them," is the way Fairfax Del. Vincent F. Callahan Jr. puts it.

Callahan, who made one of Durrette's nominating speeches in Roanoke and didn't see trouble coming even up to the moment of balloting, says his friend "got hit from the right" by Coleman.

In time with much of the Northern Virginia delegation in the assembly, Durrette came to be regarded as a moderate. He pushed for several progressive reforms in the legislature and once helped sponsor a form of "meet and confer" contract bargaining for public employes.

Coleman used this and other issues to portray Durrette as the less conservative of the two. The appeal worked so well that a third of Durrette's own Fairfax County constituents in the convention delegation -- aided by what Callahan says was Coleman's popularity with women -- cast their votes for the then little-known state senator from Staunton.

"I was mislabeled a moderate," Durrette claims. "I have conservative roots. I started the Conservative Society at Washington and Lee. I was a Goldwater supporter. I supported Reagan in 1976."

The only black mark on his conservative report card, he acknowledges, was his sponsorship, early in his legislative career, of a bill to allow public employe groups to confer with their employers. It was seen as a step toward giving public workers the right to organize unions.

Durrette says he had changed his stand two years before the convention, a switch that cost him the endorsement of a teacher groups in his 1975 election campaign.

After losing the nomination, Durrette declined a chance to get back in the assembly race because "the combination of a law practice and the General Assembly had become a great personal and financial burden" on his wife and six children.

He considered running for the State Senate last fall but decided instead to start preparing for another race for attorney general.

Although not a candidate himself, Durrette remained active in Virginia politics. He was Richard Obenshain's floor manager at the convention that nominated Obenshain for the U.S. Senate in 1978 and then was active in John Warner's 1978 Senate campaign after Obenshain died in a plane crash. He continues to serve on several state advisory boards.

Although no one has even hinted about challenging him for the nomination, Durrette does have some political detractors.

"Wyatt's not the favorite of moderates by any means," huffs one Northern Virginia Republican woman who worries that Durrette has become the darling "of a lot of rightwingers that would just as soon take us back 100 years."

But Mitchell says Durrette "comes about as close to being universally accepted as anyone I know . . . I would be nothing short of astonished if he didn't get the nomination, probably without a contest."

That most certainly won't be the case with other statewide party posts. The battle for the GOP lieutenant governor nomination is "where the action will be" next year, says Callahan. State Sen. Nathan Miller of Bridgewater; Winchester publisher Thomas Byrd, and Guy Farley, a Warrenton attorney who led the conservative faction in the state's national GOP convention delegation, are said to be jockeying for the best advantage in that nomination race.

Coleman is expected to walk away with the GOP nomination for governor, although Farley is reportedly interested in that nomination contest, too.