It was the kind of warmup the Democrats couldn't have staged better themselves. Barely five blocks from the convention center where Virginia Democrats were gathering to nominate their state ticket, the Republicans were campaigning -- and they were on the defensive.

Wyatt B. Durrette, a Richmond attorney fresh from his own nomination as the GOP's candidate for governor last weekend, stood before reporters, flailing his arms and arguing plaintively. "I'm not sure what makes them exciting or us not exciting," he said, but added that that perception "sure has caught on."

As Durrette spoke, Democrats were opening their nominating convention, planning to nominate a ticket that some Republicans have called more exciting than theirs because for the first time it contains a woman and a black.

But while they basked in party unity -- there are no contested races to be settled -- some Democrats are tempering their optimism with apprehension. There are some concerns that a ticket that includes a black and a woman may not necessarily translate into a winning ticket in the fall elections.

"I don't think there's any question they the Republicans are going to attack the ticket by showing how liberal it is," said state Sen. L. Douglas Wilder, a black Richmond attorney who expects to be the Democratic candidate for lieutenant governor.

"I'm definitely the underdog," said Wilder, adding that if there are defections from the Democrats, he will be the cause. "I don't think anyone will walk away from the other two candidates . If any walkaway occurs, it will be on my spot on the ticket."

The Democrats are hoping to use the popularity of incumbent Gov. Charles S. Robb, son-in-law of the late President Lyndon B. Johnson, along with their convention slogan, "Building on the Best." Under Virginia law, Robb cannot succeed himself, but the accomplishments of his term are clearly going to be an underpinning of the Democratic campaign.

"With slow, steady, workmanlike style, he has changed the face of Virginia," Wilder said of Robb.

Even the Republicans say they are wary of Robb.

"I'm not running against him," Durrette said in a press conference at the General Assembly Building at the end of five-day campaign swing around the state. "I'm running against Jerry Baliles."

In his acceptance speech last week in Norfolk, Durrette in mocking tones repeatedly lashed out at Baliles, the anticipated Democratic nominee, as an unworthy heir to Robb.

Durrette charged that Baliles is more in tune with the national Democratic Party, a charge that brings scoffs from Baliles.

"I don't think they can make it stick," Baliles said in a preconvention interview with Washington Post reporters and editors.

Wilder, in a separate interview, agreed with Baliles' assessment that the Republicans may be counting too heavily on Reagan-style, profamily conservative rhetoric.

"You can't just apple pie it to leadership," said Wilder, who will be opposed by Republican state Sen. John H. Chichester of Fredericksburg in the Nov. 5 elections.

The other member of the Democratic ticket is expected to be state Del. Mary Sue Terry of rural Patrick County, who is running to succeed Baliles as state attorney general. Her GOP opponent is state Del. W.R. (Buster) O'Brien of Virginia Beach.

Both Wilder and Terry said they were surprised they were able to secure the nominations without opposition.

Terry, 37, attributed her lack of opposition to her early start on a campaign that began almost two years ago.

Wilder, 53, said he ended up with an uncontested nomination because of indecision by potential opponents. Despite the early lead in his campaign for the second spot on the ticket, Wilder said he still has not assembled a campaign staff or hired a campaign manager.

Tonight the convention adopted resolutions calling for the passage of the Equal Rights Amendment, voter registration by party and a statewide Democratic primary to select party candidates.