WILMINGTON, DEL., JUNE 9 -- Sen. Joseph R. Biden Jr. (D-Del.) launched his candidacy for the Democratic presidential nomination here today with a stark assessment of the values, ethics and standards of the American people and their political institutions.

"Discontent over the failure of our political system is rampant throughout our citizenry," said Biden, 44, a third-term senator and chairman of the Senate Judiciary Committee. "And bluntly, it is in this gathering of discontent that my candidacy intends to find its voice."

In a speech to several thousand home-town supporters at a noon rally in front of the train station -- and redelivered later in the day in the rotunda of the Russell Senate Office Building -- Biden chose to offer neither policy prescriptions nor ideological constructs to rescue what he called "a nation at risk."

Rather, he spelled out the problems that concern him the most -- children in poverty, education, drug abuse, the environment, the nuclear arms race, economic and trade competitiveness, the homeless -- and said that "this campaign must convince America that our future cannot depend on the government alone."

"The government can lead. It can be the catalyst for our society. But the ultimate solutions will lie in the attitudes and actions of our people.

"I fervently believe that our people are ready and anxious, and that they will rise to this challenge and opportunity like a mighty river surging through the public life of America."

He said that as president he would challenge a public "lulled by the anthem of self-interest" to "rekindle the fire of our idealism" in a renewed spirit of community, caring and compassion.

He also said he would try to motivate economic growth with blunt we-have-met-enemy-and-he-is-us pep talks to American workers.

"I would tell the American people the truth: that no protectionist trade law can solve our economic problems when their workers work harder than ours; their managers manage better than ours and their goods and services are of a higher quality than ours. It is a bitter truth but one that must be told. And as president, I would tell our people that we must demand better of our nation, better of ourselves and better of our political society."

This bitter-pill oratory has been a Biden trademark for much of the last decade. And he and his strategists say that they believe there is a morning-after national mood in the electorate in final months of the Reagan presidency that makes voters receptive to such a message combined with a summons to renewed excellence.

"You run for president and people want to hear the straight story," said senior political adviser Thomas Donilon. "The speech was intended more as a challenge than an attack." The speech was drafted with the help of Patrick Caddell, who was ad adviser to President Jimmy Carter and played a major role in Carter's 1979 "malaise" speech calling on Americans to sacrifice during the energy crisis.

A part of the Biden message is explicitly generational: "We have the chance to bend history just a little bit," he said, referring to the generation of Americans, the "Baby Boomers," born immediately after World War II. "The clarion call for my generation is not 'It's our turn' but rather 'It's our moment of obligation and opportunity.' "

Biden is the fifth Democrat formally to enter a race that since the collapse of Gary's Hart's candidacy has had no clear-cut leader. He was introduced here today by his national campaign cochairman, Sen. Daniel K. Inouye (D-Hawaii), head of the Senate select committee on the Iran-contra affair. "I left Fawn Hall in Washington to be here with Joe Biden," Inouye quipped to an audience that included several dozen hard-hats clinging to steel girders of an nearby office building contruction site.

Inouye referred to the "most horrible tragedy" that befell Biden as a 29-year-old senator-elect: an automobile accident that killed his first wife and daughter. Biden staged his announcement in front of the train station that symbolizes his devotion to family: He has commuted to Washington by train for the past 15 years to stay close to his family. He was joined onstage today by his second wife, Jill, a teacher, his three children and 20 members of his extended family, including his sister and national cochair, Valerie Biden Owens.

In the audience were half a dozen members of Congress and political leaders from Iowa and New Hampshire, two key early states where Biden -- despite a poor showing in national polls -- has built an impressive cache of endorsements.

Arthur Davis, a former Iowa Democratic chairman, said that if Biden's standing in the polls -- one percent nationally and 3 percent in Iowa -- does not improve by the end of the summer, "We would start to have problems." But, he said, at this early stage, "I haven't had any trouble recruiting anyone." Indeed, tonight Biden gave his speech a third time, at a Des Moines rally of several hundred, and released a list of 1,250 supporters that is considered an organizational coup for his campaign.

Davis said he is supporting Biden because "after Reagan, people are going to want an intellectual contrast, but they also want a leader who can communicate."

Throughout his career, Biden has built a reputation around his passionate speaking style. In the weeks preceding the announcement, he set out to put some meat on his message with policy addresses on economic growth, trade and foreign policy and child welfare -- speeches in which he rejected the "rigid orthodoxies" of left and right and called for pragmatic solutions.

For example, he said today that the nation cannot accept "the naivete of free traders . . . {nor} the morally bankrupt, easy answers of protectionism." Though he did not spell it out today, Biden has proposed trade retaliation, in the form of tariffs, against trading partners who refuse to remove unfair barriers. He also warned against succumbing to an "isolationist" instinct in foreign policy and said development of the Strategic Defense Initiative -- Reagan's space-based anti-missile plan -- would lead to the "ravaging of our economic capital, nuclearizing the heavens and yielding the fate of our children's world to the malfunction of a computer."

But only a few passages of the speech dwelt on such specifics. Rather he delivered a more thematic critique of the very process of national political life.

"National debate has become a great pantomime, where the standard of judgment is no longer real results, but the flickering image of seriousness, skillfully crafted to squeeze into a 30-second spot on the nightly news. Have a problem? We have an answer -- but rarely a solution. In this world, all emotion is suspect -- the accepted style is smooth, antiseptic and passionless," he said.