Former Senate majority leader Howard H. Baker Jr. (R-Tenn.), who is exploring a presidential bid in 1988, yesterday called for enactment of new taxes dedicated to reduction of the national debt along lines similar to proposals made by Democratic nominee Walter F. Mondale during the 1984 presidential campaign.

"It ain't what Walter Mondale said, but who said it," Baker argued. In a direct challenge to the GOP's supply-side wing, Baker referred favorably to Mondale's controversial promise to raise taxes to reduce the deficit, and declared that President Reagan's opposition to tax increases is "wrong."

"There are some things only a Republican can do and some things only a Democrat can do," Baker said at a breakfast session with reporters. "It is my hope that for a Republican to propose a tax hike will be an exercise in realism."

On another political front, Senate Majority Leader Robert J. Dole (R-Kan.), who also may seek the GOP nomination, announced the appointment of Donald J. Devine, former head of the Office of Personnel Management, as interim chief of his political action committee, Campaign America.

Devine, who withdrew his nomination for reappointment to the OPM post after it became clear that the Senate Governmental Affairs Committee would reject it, is to serve at least through 1985.

A possible challenger to Sen. Charles McC. Mathias Jr. (R-Md.), Devine has strong credentials within the Republican Party's conservative wing, which has tangled with Dole over the years.

At the breakfast session, Baker disclosed that, in addition to his Republican Majority Fund, a PAC designed to help Republican House and Senate candidates, he has set up a separate presidential "exploratory" PAC, the Baker Fund, which has pledges of $300,000.

"You should assume I want to run," Baker said. "Wanting to be president is like getting malaria: You never really get over it."

Baker declined to specify tax increase revenue goals, but he indicated support for either an oil import fee or an income surtax. The tax should be dedicated to reducing the national debt, he said.

Also yesterday, the Federal Election Commission received reports from PACs for four potential presidential candidates: Dole, Baker, Vice President Bush and Rep. Jack Kemp (R-N.Y.). Bush's Fund For America's Future, formed April 25, led with $816,344. Kemp's Campaign for Prosperity reported receipts of $733,241; Dole's PAC, $88,304, and Baker's, $507,684, for the first six months of the year.