Democrat Michael Dukakis said Tuesday he was gaining ground on George Bush whom he called a failure as vice president. Republican Bush proposed a $100 million umbrella organization to encourage voluntarism, saying, "I want our affluent to help our poor."

While the two White House contenders campaigned in critical states - Dukakis in Illinois and Bush in California - the vice presidential candidates devoted their time to preparing for Wednesday night's debate.Republican Dan Quayle, who has studied at an undisclosed location in Washington, D.C., was leaving Tuesday for Omaha, Neb., for the debate, as was Democrat Lloyd Bentsen, who did his final preparations in Austin, Texas.

Dukakis, at Northwestern University in Evanston, Ill., said Bush had failed in five missions: as part of an administration effort to increase U.S. sales in Japan, as head of task forces on regulatory reform, drug interdiction and international terrorism, and in an effort to recommend banking reforms.

"Mr. Bush was given five important missions by this administration and he failed every one. And that was before they asked him to pick a running mate in this election," Dukakis said.

The Massachusetts governor, slightly behind Bush in recent polls, said he was "beginning to turn this race around." He said the final weeks would be "tough and competitive."

Bush, in Sacramento, Calif., proposed creation of "Youth Engaged in Service to America," an organization chaired by the president that "will work with existing youth programs and will put an emphasis on programs that are started in our schools."

The organization might develop some new volunteer programs but mostly would work in partnership with programs already under way, such as the Peace Corps and others, said Bush campaign adviser Loret Ruppe, director of the Peace Corps.

Bush said, "I want our affluent to help our poor. I want our young to help our elderly. . . . I want the young men and women of our tree-lined suburbs to get on a bus, or the subway, or the metro, and go into the cities where the want is."

On Monday, Dukakis promised a presidency that would enforce civil rights laws while Bush pledged support for development of a space station in his administration.

With the election five weeks away, the Democratic presidential nominee told black supporters on Chicago's South Side Monday night that the nation will be deciding between "two different futures, two different roads to travel."

The vice president, who earlier Monday welcomed the return of the space shuttle Discovery and its five-man crew, told a rally in Redding, Calif., that he is committed to the creation of an operational space station by 1996.

"This goal is achievable, sensible . . . and we will meet that goal," Bush said.