Jackson Climbs Aboard as Clinton Sails Into N.Y. : Campaign: After warm welcomes in Tennessee, the presidential candidate wins long-awaited endorsement.

After a day of celebratory campaigning in Tennessee that included a well-received appearance before the NAACP, a confident and triumphant Bill Clinton arrived in New York on Saturday to begin the nearly weeklong process that will culminate with his acceptance of the Democratic presidential nomination.

Shortly after arriving here, Clinton picked up the long-anticipated--but long-delayed--endorsement of the Rev. Jesse Jackson, with whom he had bickered through much of the primary season.

Jackson used part of his talk show on CNN to offer a critique of what he said were two political parties that “more and more people view . . . as two sides of the same coin,” and to describe some of his remaining differences with Clinton. But he then declared that “on Nov. 3, I have decided to vote for Bill Clinton . . .”

The endorsement had been the subject of tense negotiations for days, with Democratic National Chairman Ronald H. Brown, a former Jackson aide, serving as the intermediary. Although Clinton aides had expressed confidence they could attract black votes even without Jackson’s support, they nonetheless welcomed the endorsement, which removes one of the few remaining threats to their plans for a smooth, conflict-free convention.

“It’s a good sign the party’s coming together,” said Clinton’s communication director, George Stephanopoulos. “We know that what unites us is a powerful commitment to economic opportunity.”

In other convention developments Saturday:

* Former California Gov. Edmund G. (Jerry) Brown Jr.--the last foe Clinton vanquished on his march to the nomination--arrived in New York and began writing a speech he plans to deliver to the convention Wednesday night when his name is placed in nomination. Using that occasion for his speech apparently will allow Brown to thwart any effort to keep him completely off the podium unless he endorses the Democratic ticket. Brown gave no sign Saturday that he was prepared to meet that condition. Instead, he denounced the platform crafted by the Clinton forces as “full of gooey and imprecise language.”

* In a probable preview of protests to come, a dozen anti-abortion activists held a morning prayer vigil in front of the Eastern Women’s Center, which is five blocks from Madison Square Garden, where the convention convenes Monday. They were outnumbered by 300 abortion-rights demonstrators. Police kept both sides separated. And Saturday night, ACT UP, the AIDS Coalition to Unleash Power, crashed a large party for the media, denouncing coverage of the AIDS crisis. During the convention, groups ranging from the Coalition to End Violence Against Women to the Justice for Cyprus Committee plan to make their views known in the streets near the convention hall.

* Many of the convention’s 4,928 delegates and alternates checked into their hotels throughout midtown Manhattan on Saturday and for most, the first order of business seemed to be walking around town during the afternoon and partying at night. The conventioneers eagerly took in the city’s sights, from Times Square to 5th Avenue. By evening, they swarmed into restaurants and attended the first of the dozens of parties scheduled for the next few days. Clinton arrived at New York’s La Guardia Airport shortly before nightfall, where he was greeted by Mayor David N. Dinkins.

Dinkins praised the Democrats for bring their convention to his city, noting that its economy would benefit from the spending of the conventioneers--and those covering them.

“But the best business will be (the nomination of) a new President and new vice president,” he said.

For his part, Clinton claimed he was “glad to be back in New York,” a city his campaign rejoiced in leaving three months ago after winning the state’s primary in a brutal fight dominated by tabloids and talk shows.

Clinton’s mood now is in sharp contrast to those trying days. Appearing buoyant and energetic, Clinton and Sen. Albert Gore Jr. of Tennessee, whom he tabbed Thursday as his vice presidential choice, began the day in Gore’s hometown of Carthage, Tenn., for a rally marked by prayers and folksy witticisms. The event, which included the two men’s wives and children, sought to portray the running mates as country boys who made good but have not forgotten their rural Southern roots and values.

Clinton also displayed his folksy side. Standing in the 90-degree heat, he told Gore’s hometown crowd of several thousand that he “resented” the fact that his running mate is “younger, better-looking and thinner than I am.”

“But I’ll get over it. Running for President makes you humble, if nothing else does.”

As he continued, Clinton stressed a theme that his strategists hope to make central to the campaign: the idea that he and Gore exemplify American values of hard work and community, in contrast to what they charge is a Republican emphasis on individual greed.

“When I look out at this crowd today, I see a bunch of winners who deserve a government that helps them win. You deserve better, and we’re going to give it to you,” Clinton said.

From Carthage, the pair traveled to Nashville, where they attended the National Assn. for the Advancement of Colored People convention. They promised the predominantly black audience that their Administration would, in Clinton’s words, “make economic opportunity the civil rights issue of the 1990s.”

Clinton and Gore received a rousing welcome at the group’s national convention, in stark contrast to the cool response to prospective independent candidate Ross Perot, whose speech earlier in the day caused a flap when he made references to “you people” and “your people.”

Clinton, by contrast, began his speech: “I am glad to be here today to celebrate all of us together.” And he closed by exhorting the crowd to join him next year at the White House to sing the black anthem, “Lift Every Voice and Sing.”

As he stepped down from the podium, the organist began playing the music, and Clinton joined his audience in song.

President Bush was invited to the convention but declined.

Gore drew cheers and applause when he told the NAACP that Democratic hopes of recapturing the White House depend on black voters.

“We need your help. We want you to be a part of the winning team. In order for us to win, it must be a victory for us.”

Jackson’s endorsement may help Clinton and Gore attract those votes, although the ability--or willingness--of the civil rights leader to galvanize support remains in doubt.

His Clinton endorsement had been in doubt because of a history of tension between the two men. While Clinton has sought to move the Democratic Party in a more moderate direction, Jackson has led those who have tried to move the party to the left.

On a more personal level, Jackson campaigned frequently with Brown during the New York primary and influenced several major local unions to endorse him--a move deeply resented by Clinton. The ill feeling deepened when Clinton appeared at a meeting of Jackson’s Rainbow Coalition last month and criticized the group’s willingness to host rap singer Sister Souljah, who had made statements that appeared to condone racial violence.

Even while making his endorsement, Jackson emphasized several points of difference with Clinton, including Jackson’s opposition to the death penalty.

“Clinton and Gore at their best,” Jackson told his television audience, “are the most live option” to implement a progressive agenda. But, he added, “the candidates, the platform and the needs of the people must come closer together.”

Times staff writer Michael Ross contributed to this story.