OS ANGELES - Hillary Rodham Clinton last night delivered both a soulful message - thanking the American people for ''your faith and support in good times and in bad'' - and a spirited call to extend the Clinton era by electing Al Gore and Democratic candidates like her.
It was a remarkable night with the president saying goodbye to an adoring party after eight eventful White House years, and Mrs. Clinton emerging from her own tumultuous tenure as first lady and wronged wife to propel herself into a high-profile political career of her own.
When Maryland Senator Barbara Mikulski introduced Mrs. Clinton as the next senator from New York, a great roar filled the Staples Center and delegates waved a blue sea of ''Hillary!'' signs to the refrain of ''New York, New York.'' As Mrs. Clinton began her remarks, the crowd interrupted her with the noisy chant of ''Hillary, Hillary, Hillary!''
''Don't let anyone tell you this election doesn't matter,'' said Mrs. Clinton, who is locked in a tight race to succeed retiring Democratic Senator Daniel Patrick Moynihan of New York. ''The stakes in November are the biggest for those who are the littlest among us.''
Mrs. Clinton, a 52-year-old lawyer and Wellesley College graduate, reminded the audience that she has been a family advocate since working for the Children's Defense Fund 30 years ago. She noted that ''leave no child behind'' was the group's slogan. It was also a theme at the Republican convention in Philadelphia two weeks ago.
''We've made great progress in the last eight years, but we still have a lot of work to do,'' Mrs. Clinton said. ''Because when a child can't go to school without fearing guns and violence, that's a child left behind. When a child's illness is not treated because a hard-working parent can't afford health insurance, that's a child left behind.
''When a child struggles to learn in an overcrowded classroom, that's a child left behind,'' she said, telling delegates that as president, Al Gore would leave no child behind.
In her 15-minute speech, delivered right before the president's, Mrs. Clinton repeated many of her campaign themes: better health care for children, pay equity for women, a raise in the minimum wage, lower taxes for working families, and an end to the media culture of violence. But a brief reference to her own domestic situation seemed the most heartfelt for Mrs. Clinton.
''The most important thing that I can say tonight is: Thank you,'' she said. ''Thank you for giving me the most extraordinary opportunity to work here at home and around the world on issues that matter most to children, women, and families.''
Her appearance capped a whirlwind Los Angeles weekend of campaigning and fund-raising that drew some criticism for overshadowing Al Gore's show. Mrs. Clinton denied that was her intention and was set to leave Los Angeles at 6 a.m. today with her husband and daughter, Chelsea, to meet up with the vice president in Michigan.
Mrs. Clinton praised her husband's ''visionary leadership'' and said ''we're a stronger, better country than we were in 1992.'' As for the vice president, she said, ''I can't wait until we watch Al Gore take the oath of office on Jan. 20, 2001.''
Later, Mrs. Clinton was seated next to her daughter high in the sports arena, listening as her husband described her as ''someone who has always been there for our family, and she will always be there for the families of New York and America.''
The first lady's appearance was deemed an opportunity for her to showcase her candidacy and boost her campaign. She previewed it yesterday in network interviews, appearances before the black and Hispanic Democratic caucuses, at a Hollywood salute to women in Congress, and at a New York delegation breakfast.
''There is only one choice in this election, whether we're talking about president, vice president, or senator from New York, and the right choice is to keep going forward together,'' said Mrs. Clinton as she was introduced as ''Senator Hillary Clinton'' to the Empire State gathering at the Century Plaza Hotel.
Applause from the New Yorkers was sustained but not enthusiastic as Mrs. Clinton thanked the delegates for their support and promised to ''hit the ground running.''
The reaction probably reflected the anxiety of New York Democrats who thought they had a winning celebrity candidate in Mrs. Clinton. After 13 months of intense campaigning, the first lady is in an unexpectedly tight race with Representative Rick Lazio, a Long Island Republican who has no national reputation and entered the contest late, after New York Mayor Rudolph Giuliani dropped out because of prostate cancer.
Mrs. Clinton continues to have trouble convincing white, suburban women in New York that she is not exploiting either her marital woes or her position to win a Senate seat. In an interview with Larry King last night on CNN, Mrs. Clinton refused to revisit her husband's infidelity, even though President Clinton spoke last week of the pain it caused his family.
''You know that's my business, and I don't talk about my personal business, and I feel strongly that what goes on in a marriage or a family should remain in that marriage and in that family,'' Mrs. Clinton told King.
At a luncheon yesterday honoring women in Congress, Mrs. Clinton said it was ''abolutely critical'' to elect women candidates who will protect abortion rights and not roll back gun-control measures. In her speech, Mrs. Clinton talked about gun control but only mentioned abortion in citing the record of Senator Joseph I. Lieberman of Connecticut, who supports legal abortion. Lieberman has been tapped as Gore's running mate.
Her campaign has been quick to point out that Mrs. Clinton has a prominent speaking role at the Democratic convention, while Lazio turned down what he considered a bit part on the GOP program two weeks ago in Philadelphia.
While Mrs. Clinton takes a short vacation later this week at Lake Placid, N.Y., she will maintain a shadow presence in Los Angeles. Dozens of ''Hillary ambassadors'' from New York have been organized by her campaign to raise money, distribute literature, and promote Mrs. Clinton's candidacy.
Judith Hope, the state chairman, called Mrs. Clinton's campaigning here ''one more step in her bonding with the New York Democratic Party.
''She is giving a very important speech, she is spending time with the New York delegation, and she is raising money,'' Hope said. ''Those are three really important things for her.''
