House Republican leaders on March 4 nearly muffed the golden opportunity handed them by Jimmy Carter's imitation of Herbert Hoover's economics, and they may yet be tempted to out-Hoover the president.

President Carter's response to the horrors of 18 percent inflation: no price-wage freeze, no tax reduction, deeper spending cuts, a budget balanced by tax increases. That is not only the New Deal repudiated but resembles Hoover's economics that condemned the Republican Party to a half-century in the wilderness, from which it has not yet emerged,

To counter Carter's draconian econimmics, the Republicans have the Kemp-Roth bill's steady income tax reduction intended to fight inflation by restoring prosperity. But what Carter is doing looks so much like old-fashioned Republicanism that old-fashioned Republicans can scarcely resist it. Minority leader John Rhodes put out word that this new-fangled tax reduction would have to be dropped while Republicans outdo Carter with even deeper spending cuts.

However, younger Republican congressmen committed to Kemp-Roth -- including Rep. Jack Kemp himself -- virorously dissented at the secret March 4 session. "I really believe we saved the tax cut," one Kemp supporter told us. Nevertheless, the Republicans may be too timid to vividly contrast with Carter's massive political gamble.

It is a gamble, because it marks this unprecedented Democratic response to economic adversity: Americans, tighten your belts! Presidential aides, noting public demands for less government spending, consider this good politics. But how can it compete with Sen. Edward Kennedy's price controls and Ronald Reagan's tax cuts?

The answer by one of Carter's most trusted advisers: "The federal government has been profligate over the years, and now we are tightening our belts. The American people also have to tighten their belts, until we can lick this." That can be summed up in one word: austerity.

The current Carter budget's most painful austerity is predicating budget-balancing on $75 billion of additional federal revenue, including $49 billion in new taxes (the oil "windfall" profits tax, Social Security tax hikes and inflationary jumps into higher individual tax brackets). This stunning Carter tax increase is mostly ignored on the presidential campaign trail, mentioned only once in a while by Reagan and never by his adversaries.

It was mentioned often at the March 4 meeting, however, by congressmen opposed to out-Hoovering Carter. The lead argument against abandoning tax reduction was delivered by the highly respected William Frenzel of Minnesota, followed by California's Clair Burgener and Michigan's David Stockman. Kemp and Georgia's Newt Gingrich, representing the freshman class, chimed in.

The resulting consensus: House Republicans will press for a balanced budget and a tax reduction. Kemp regards that as inglorious retreat, but his supporters believe at least declaring the goal of a balanced budget is needed to make tax reduction credible.

More damaging to Kemp's economic strategy than such lip service to old-fashioned Republicans is the shrinking of his tax reduction. Congressmen left the March 4 meeting talking about a $25 billion one-year tax cut -- a far cry from Kemp-Roth's 10 percent annual drop in individual rates. Indeed, the Republicans seem uneasy about advancing Prof. Arthur Laffer's revolutionary thesis that tax rate reductions increase tax revenues.

Still, differences between Republicans and Democrats are clear. The president so abhors tax reduction, fearing revenue loss would delay his balanced budget, that he rejected pleas from all advisers to include accelerated depreciation in the current budget. Even such Democratic tax-cutters as Sen. Lloyd Bentsen of Texas are pulling back; Bentsen, the Joint Economic Committee chairman, now gives a balanced budget first priority with tax reduction delayed until 1981.

The prospect that votes will have a real choice are strengthened by Reagan's revival as Republican front-runner; he is a late-blooming but increasingly committed tax-cutter. So is Reagan's national chairman, Sen. Paul Laxalt of Nevada. Asked to choose between a balanced budget and tax reduction, the stolidly conservative Laxalt replied: "If the decision of going one way or the other were left to me, I would go with the tax cuts."

The White House, operating on the dubious surmise that the public rejected Kemp-Roth in 1978, feels certan voters will choose budget balancing. rBut traveling through his Michigan district two days after the Republican strategy meeting, Dave Stockman heard lots more complaints about higher taxes than anything else. This election may prove an epic test of who is right -- unless Republicans decide to compete with Carter in imitation of Herbert Hoover.