LOS ANGELES - Democrats stirred memories of John F. Kennedy's ''New Frontier'' at their national convention Tuesday as Al Gore campaigned westward to claim the party's presidential nomination. The vice president vowed to extend the current economic expansion and said, ''We're not turning back.''
President Clinton ''worked hard to get the economy right,'' said Gore in Michigan, at a joint appearance with the president meant to pass the torch of party leadership to the Democrats' 2000 nominee. ''I'm not going to let the other side wreck it.''
Half a continent away, a parade of speakers made the case for four more years for the Democrats in oratory designed to strengthen Gore's support among the party's traditional base as well as rekindle the excitement of the Kennedy era.
''Our country needs a Democratic president, a Democratic Congress and more important, a Democratic conscience,'' said Bill Bradley, Gore's only rival in last winter's primaries.
Bradley jabbed at Republican candidate George W. Bush, saying that ''as Democrats, we're not conservative with our compassion,'' pointing to the party's longtime commitment to civil rights, the minimum wage and environmental causes.
Delegates approved Gore's platform, a document crafted to stress fiscal caution while providing provide contrasts with the Republicans for the campaign ahead. ''If America is to secure prosperity, progress, peace and security for all, we cannot afford to go back,'' it said, seconding Gore's remarks in the Midwest.
The platform supports abortion rights and gay rights and opposes school vouchers and partial privatization of Social Security. It also calls for paying off the publicly held national debt in 12 years, while providing for a prescription drug benefit under Medicare and tax cuts targeted to the middle class.
Demonstrators for a variety of causes - women's rights, animal rights and public education among them - paraded near the Staples Center. Police reported 25 arrests.
Gore arrives in the convention city Wednesday, a few hours before delegates nominate him by acclamation. He delivers his acceptance speech on Thursday, the beginning of the fall campaign to win four more years for Democrats in the White House.
There were one or two discordant notes, including podium remarks by Sen. Russell Feingold, a champion of an overhaul of the campaign finance system. The Wisconsin senator spoke of his ''concern and dismay that soft money fund raising has become so much a part of this convention. It should not be.'' He urged the party to ban it in future conventions.
Convention delegates settled in for an afternoon and evening of speechmaking.
''We made history (in 1960) by summoning the best of our country, challenging Americans to serve,'' said Kathleen Kennedy Townsend, niece of the late president and lieutenant governor of Maryland. ''This year, with renewed resolve, we'll make history again.''
Caroline Kennedy was using a featured speaking slot to hark back to her father, who beckoned America toward a ''New Frontier'' in his acceptance speech 40 years ago in Los Angeles. Sen. Edward M. Kennedy had his turn at the podium, the brother of the slain president as well as the most prominent and persistent liberal of his generation.
The roster of speakers was drawn from the full range of Democratic constituencies, including Jesse Jackson, the civil rights leader who twice sought the party's nomination, Kate Michelman, head of NARAL, an abortion-rights group; Elizabeth Birch of the gay and lesbian advocacy group Human Rights Campaign, and union president Gerald McEntee.
Gore tapped Rep. Harold Ford, a young black lawmaker from his home state of Tennessee, to deliver the convention's keynote address.
The polls underscored the challenge ahead for Gore, and explained the evening program, as well.
He trails Bush by margins ranging from three points to double digits, and a new survey showed he has yet to either solidify his Democratic base or gain political credit for the country's strong economy.
A Los Angeles Times poll taken on the weekend before the convention found that 49 percent of those surveyed said Gore deserves no credit for the economic good times. Also troubling for Gore, the same poll said the vice president has the support of only 78 percent of Democrats, with Bush siphoning off 18 percent. Bush, by contrast, has the backing of 95 percent of Republicans, and leads the vice president by 16 percent among independents.
Gore's vice presidential running mate, Sen. Joseph Lieberman, was in California, where he sought to reassure black voters about his views on affirmative action. ''I want to talk very specifically about it,'' he told black convention delegates. ''I have supported affirmative action. I do support affirmative action. And I will support affirmative action,'' he said to applause.
Gore and Clinton campaigned together in Monroe, Mich. a blue-collar swing district where they had appeared in their successful 1992 campaign. Gore thanked Clinton for the endorsement he delivered from the convention podium on Monday night. He noted the prosperity of the past eight years, and said, ''we're just getting started. We're not turning back.''
In a slap at Republicans, Gore said, ''Why would we squander these historic surpluses on tax giveaways that bust the budget and comfort the comfortable? Let's invest in health care, education, a secure retirement and middle class tax cuts.''
He also said he would ''not go along with any plan to privatize Social Security.''
In Los Angeles, delegates eagerly awaited his nomination and speech.
Some reflected, as well, as the past.
One, Mike Vinich, of Wyoming, was on the convention floor 40 years ago when his delegation gave John F. Kennedy the delegates he needed to clinch a contested nomination.
''We were all split up,'' he recalled. ''There were Kennedy delegates and (Lyndon) Johnson delegates and Adlai Stevenson men.''
Vinich recalled telling his delegation chairman that Kennedy ''only needs 13 votes; we've got 15. We can give him the nomination and make a place in history.''
They did, and Vinich said, ''the convention just went wild. What a moment.''