ASHINGTON - Vice President Al Gore straddled a picket line problem yesterday, trying to bridge the gap between two Democratic constituencies gathered on opposite sides of a hotel's walls.
With striking union workers picketing outside the Grand Hyatt here, and the National Summit on Africa waiting indoors, Gore was torn.
Gore avoided crossing the picket line by addressing the forum across a telephone line.
''Hello? Can you hear me?'' Gore's voice called into the cavernous ballroom over the clanking of silverware and china as 1,400 summit delegates dug into a lunch of salmon and avocado salad. Huge television screens at the front of the room focused on an empty podium.
''The hotel workers' union local 25 is picketing, and in solidarity with these workers, I will not cross that picket line,'' Gore told audience members, some of whom applauded. ''At the same time, I did not want to miss the chance to share some words with you about the importance of our protecting the world today.''
Gore followed President Clinton, who spoke to the group a day earlier - at a convention center with no picket line. Both talked about helping Africa's developing nations by forgiving some of their debt, enacting favorable trade policies, and improving public health by fighting AIDS.
Bill Bradley spokeswoman Kristen Ludecke said the former New Jersey senator offered to appear before the Africa meeting via satellite, but organizers told him they preferred a personal appearance. Walter C. Carrington, the former US ambassador to Nigeria, spoke to the group on behalf of Bradley, who ''cares deeply about the connection between the United States and Africa,'' Ludecke said.
In another bid for minority votes, Gore yesterday released an ad in which he speaks Spanish and pledges to improve schools, Medicare, and the fight against crime. A second ad released yesterday revises an ad of just two days ago to add abortion rights to a list of issues for which he has fought; Bradley had just begun airing an ad across the country hitting Gore for his early antiabortion votes.
Bradley also came out with a new ad, highlights of his life story, as he introduces himself to voters in states with upcoming primaries.
''When Bill Bradley wins, you win,'' the ad says. ''But first you've gotta give him the ball.''
At the African forum, Gore's participation got a mixed reaction.
Union members, who picketed on the sidewalk in steady sleet, appreciated Gore's gesture.
''It doesn't count'' as crossing the picket line, said Nancy Wallace, a member of the Hotel Employees and Restaurant Employees International Union.
''We're thrilled,'' said Ron Richardson, general vice president of the group.
But delegates to the conference were less enthusiastic.
''I'm offended,'' said Christian Ibenacho, of Ontario, Calif., who nonetheless said he would vote for Gore. ''We're also his constituency. He should have come.''
On Monday, Gore and Bradley will debate race relations at the Apollo Theater in Harlem. Bradley, campaigning yesterday at a school in Harlem, invoked a bit of his past by talking about dreaming big. He recalled his efforts, while a New York Knick, to mentor Harlem youngsters during basketball's off-season.
''I'm coming here today as someone who has been in this kind of setting a lot of times,'' Bradley told 25 students, most 13 or 14 years old, who are part of a business and computer technology ''mini-school'' within Adam Clayton Powell Jr. Middle School Academy.
