Sounding possible themes for a presidential campaign he insisted he has not yet decided on waging, New York Gov. Mario M. Cuomo yesterday portrayed Republican policy as the central cause of the economic downturn.

"The captain must change course," he declared in a National Press Club speech that mixed a tough critique of the Bush administration with some lighthearted cracks in which he seemed to be suggesting that the nation should pick a new captain.

The speech, much like a recent address by House Majority Leader Richard A. Gephardt (D-Mo.), another potential presidential candidate, seemed designed to test the salability of his themes before a Washington audience.

"For over a decade, we have adopted policies to promote a vision of economic growth that is, it seems to me, increasingly out of touch with the lives and aspirations of millions of hard-working families, policies that have yielded a system of free enterprise for the few, instead of progressive free enterprise for the many," said Cuomo.

He portrayed the severe budget difficulties facing New York state as part of a national problem, not the result of local policies. "I'm a governor who has been on the front lines dealing with a national recession who believes it is not just a recurrent cleansing phenomenon. . . . It's already a punishing experience."

Reflecting part of the general Democratic drive to restore the allegiance between the poor and the middle class that characterized the once-dominant Democratic coalition, Cuomo repeatedly stressed the difficulties facing both groups.

"Of course there is more poverty in this country. And even workers who have escaped poverty have not escaped concern or fear. Ask middle-class families, the people who are not poor. . . . Middle-class people are the people who are not poor enough to be on welfare and not rich enough to be worry-free.

"They're people who work for a living," Cuomo continued. "Not because some psychiatrist tells them it's a convenient way to fill the grim interval between birth and eternity. . . . They have to work for a living."

The middle class, Cuomo contended, "is figuring out that all through those years {of the Reagan and Bush administrations} . . . when they were being told 'Read my lips,' they believed that that meant that Washington wasn't raising their taxes. . . . They finally figured out that . . . what you {Washington and the Bush administration} didn't tell us was that was making an immense hole in the budget and you were going to fill up the hole by raising our Social Security tax."

Fielding questions after the speech, Cuomo was characteristically vague about his presidential ambitions -- "I don't have any plans" -- and dismissed current conservative calls on President Bush to adopt an "empowerment" agenda as a collection of proposals already endorsed and initiated by Democrats.

"It's a stark admission of intellectual undernourishment. . . . They have no more ideas," he said.

In one of the few specifics in his speech, Cuomo said that instead of a capital gains tax cut, Social Security taxes should be cut so that money goes directly to workers and consumers.