Michael Dukakis fired a return salvo Tuesday at George Bush, grabbing a central attack theme from the Republican nominee-to-be and charging "I don't think Bush's positions are clear on much of anything."

Bush has hit Dukakis in recent days with a barrage of criticism, saying the Massachusetts governor is inexperienced in foreign policy and waffles on the issues. On Monday, he set the tone for next week's Republican National Convention, taking advantage of a rare appearance at platform hearings to light into Dukakis."He's the stealth candidate," Bush said. "While he can't decide about the stealth bomber, he favors instead stealth policies - they can be neither seen nor heard." (Dukakis supports research and development for the supersecret bomber but has not vowed to support deployment.)

Bush stayed away from direct attacks on Dukakis Tuesday, painting himself instead as tough on crime and touting his opposition to the American Civil Liberties Union.

"There are those, like the ACLU, whose first concerns are the protection of the criminals' rights and the potential abuse of power by police," Bush told a police group in Erie, Pa. "My first concerns are the protection of law-abiding citizens and the abuse of our system of constitutional protections by thugs who can go and hire smart lawyers and find the right judges to set them free."

And the Republican vice president said liberals in Congress just duck the tough issue of drug enforcement: "Congress is full of rhetorical heroes on the issue of drugs, but when it comes to law enforcement a lot of the liberals there go AWOL."

The Democratic nominee lashed back at Bush as he flew from Boston to Cincinnati to join the final session of the National Governors Association.

Bush's foreign-policy positions were unclear, Dukakis said, with the sole exception of "this endless fiasco in Central America," where Bush supports aid to the Contra rebels in Nicaragua and Dukakis opposes it.

"I don't know. Do you know where he stands?" Dukakis said to reporters. "I don't think anybody knows where he is on these things. The only thing he's done is to express some doubt on U.S.-Soviet relations. I don't think Bush's positions are clear on much of anything."

On Monday in Cincinnati, the governors heard a farewell speech from President Reagan, with the GOP incumbent staying away from the campaign specifics but boasting of the accomplishments of his administration. "Our states, like our citizens, have known the blessings of the longest peacetime economic expansion on record," Reagan said.

Dukakis, weary of the constant pounding from Bush, whom he leads by double-digit margins in the national polls, said the public is getting tired as well.

"I think the way I'm going to win the presidency is not by responding every day to what some speechwriter has put in front of Mr. Bush," Dukakis said.

In New Orleans Tuesday, the Republican Platform Committee released a raft of working papers that would commit the party to "unequivocally reiterate the no-tax pledge" and press for a constitutional amendment to outlaw abortion.

The papers, nearly 30,000 words long, were serving as the starting point for the platform writers, who were working in seven subcommittees on a draft of the 1988 GOP platform.

The staff-written papers echoed the major policy stands of the 1984 Republican platform, with changes to reflect Bush's emphasis on such issues as child care and education.

Bush called for a party platform that will stand up well in comparison with what he called the Democrats' "document of deceit."