RALEIGH, N.C., OCT. 10 -- Jesse L. Jackson formally launched his second campaign for the Democratic presidential nomination today, telling a throng of 5,000 supporters: "I want to serve America."

Standing beneath a cloud of red, white and blue balloons, the political and civil rights leader sounded themes of patriotism, duty and opportunity in his declaration address to the national convention of the Rainbow Coalition, a political organization he founded four years ago.

"There is something wrong with our government policies today . . . but there is nothing wrong with America. America is our land. America is God's country. America has been blessed and God bless America."

The very conventionality of Jackson's message was itself a message: After a quarter-century in public life as an outsider challenging and goading the status quo, he is running this time as part of what he views as a new mainstream of Americans -- workers, farmers, minorities -- who are victims of "economic violence" meted out by multinational corporations and misguided government policies.

Jackson, 46, joins a field of five other Democratic aspirants as the only candidate never to have held elective office, and the only one to have sought the presidency before. In his 1984 campaign, he received about 18 percent of the primary and caucus votes, and about 12 percent of the delegates.

The celebrity he gained from that bid, and from his years as a civil rights and human rights leader, has placed him atop nationwide polls taken of the Democratic electorate this summer and fall; he is the choice of between one-fifth and one-quarter of Democratic voters.

Part of that lead comes from the fact that, with Gary Hart's withdrawal, the rest of the party's field is composed of state-based political figures who are still in the early phases of introducing themselves to a national audience.

Jackson delighted the crowd here today by telling them he has "earned" his high name recognition, and by tweaking his opponents. "If the other candidates had risked cold jail to fight for civil rights . . . fought with workers in the trenches . . . challenged major corporations to be fair . . . gotten prisoners out of jail," he said, delivering a lengthy list of the high points of his public life, and punctuating each with a jab, "maybe somebody would know their names."

He used his announcement to show off his political support -- releasing a 14-page endorsement list that included 15 members of Congress, 17 mayors, 84 state representatives -- all but a handful of the elected officials are black -- and hundreds of leaders from business, labor, entertainment, ethnic and issues groups.

The announcement, at the civic center here, had a revival meeting flavor of the sort that Jackson, with his background as a Baptist preacher, has always brought to politics. Supporters clasped hands, sung, swayed, prayed and "amen-ed" their way through introductory speeches from representatives of Jackson's political rainbow -- blacks, Hispanics, farmers, disabled citizens, environmentalists, Native Americans, Arab Americans, Jews, Asian Americans and labor.

While the spirit here was upbeat, there was a pervasive concern that bubbled to the surface yesterday and today about potential news media scrutiny of Jackson's private and family life in a year in which such scrutiny has become the norm.

"Jackson Backers Worry About Rumored Article," was the front-page headline in today's Raleigh News & Observer. It reported that on Friday night Marion (Rex) Harris, director of the Rainbow Coalition, warned from the podium that the Atlanta Constitution was about to publish an article about Jackson that contained "a lot of garbage," including charges of womanizing. Editors at the Atlanta Constitution denied Harris' assertion and said no such article was planned.

The Atlanta paper did report yesterday that Jackson's wife, Jacqueline, was two months pregnant with the first of the couple's five children when they were married 25 years ago. Jackson -- himself born out of wedlock -- has never tried to hide or misstate his wedding date.

The chairman of Jackson's exploratory committee, former Gary (Ind.) mayor Richard Hatcher, raised the subject of press scrutiny again from the podium today, indicating his supporters may be trying to preemptively take the bite out if any stories do appear.

"The winds of controversy will swirl around the head of our candidate and you might as well be ready for that," he told the convention.

"We must not allow anybody else to tell us who Jesse Jackson is. We know who Jesse Jackson is," Hatcher said. "It's the tallest tree that catches the most wind, and we know who the tallest tree is."

In his speech, Jackson called for the use of pension funds to make government-guaranteed investments in infrastructure repair and housing, for the payment of more taxes by profitable corporations and for a strengthened Coast Guard to attack drug traffickers.

On foreign affairs, he enunciated a "Jackson Doctrine," which calls for respecting international law, support of the principle of self-determination of human rights, and an effort led by the United States and Japan to spur economic development in the Third World.

Raising living standards in the Third World, he said, would create markets abroad for products made here and would reduce competition from "slave labor."

Jackson also announced plans today to visit troops in the Persian Gulf to "lift their spirits." He said they are "trapped in a war without clearly defined objectives."

He characterized his decision to run as a call to duty.

"As one who has had the privilege to travel around the world to retrieve Americans from dungeons and foreign jails, as one who has had the privilege to meet the great leaders of the world, I can do no less than serve my country, offer my services, my skills, my energy, my commitment to its ideals," Jackson said. "My broad-based American experience, from the humblest beginnings . . . has made my appreciation and love for America a part of my blood, my bones and my soul."