Republican leaders are unnecessarily pessimistic in their assessments of the American spirit, former Massachusetts governor and presidential candidate Michael S. Dukakis said yesterday.

"Whoever things the '50s were a golden age either wasn't conscious or doesn't know what they're talking about," Dukakis said. "Schools now are unquestionable better and there is an improvement of black and Hispanic literacy and quality of life."

More than 100 people gathered at the Kennedy School of Government to hear the Brookline native speak on "The Case for Optimism" for America.

Dressed in khakis and a Hawaiian shirt, Dukakis kept the first event of the Kennedy School's "Summer in Boston" program informal, engaging in a lengthy question-and-answer session with the audience of summer school students after his short address.

He also remained after the event to chat with students and take pictures with audience members.

Dukakis challenged Newt Gingrich and the Republican Party's Contract With America, targeting recent "nostalgia for the '50s and the environment of the house and family values."

The 1950s was a time when "Washington, D.C., the capital of the free world was as segregated as Johannesburg, South Africa," The candidate said. "African-Americans had to sit at the back of the bus; and public schools were segregated by act of Congress."

Dukakis pointed to Cold War as the focus of this supposed golden age.

"Our entire world view was contained within the prism of endless conflict with the Soviet Union," Dukakis said.

Now, Dukakis said, things have changed.

"Lest anyone tell you that public schools have deteriorated, please remind them that half the students in the '50s never graduated [from high school], particularly minorities," he said. "Blacks no longer have to take their lives in their hands in order to vote." Central to America's cause for optimism,Dukakis said, is an increased emphasis on publicservice.

The Most significant problem in the UnitedStates, he said, was not a decrease in values oropportunity, but "a growing and pervasive sense ofeconomic insecurity on the part of workingAmericans."

The Republicans have "no commitment to thenecessity of having every job carry with it healthinsurance," Dukakis said.

Another problem was the suggestion thatfederally-funded student loans be cut. "If you'repoor enough, you can get scholarships. But what doyou do if you're in the middle?," he asked.

After sharing his views on talk radio,politicians' images and drugs with questionersfrom the audience, Dukakis charged students withbecoming involved with the political process inorder to change the political mood in the UnitedStates.

"Unless guys like you get into this seriouslyand actively, American democracy isn't going toproduce and achieve what it ought to," he said."This is nuts and bolts politics, folk--it's notrocket science. We need to go door to door,neighborhood to neighborhood to get peopleinvolved.