What mandate will emerge after the dust from the election has settled on Nov. 7, and what will that mean for the policies that will govern us all? One possibility is a Reagan mandate - one that would be interpreted as an affirmation of the direction of the past four years and a boost for more in the next four. That is possible, but not likely. Far more likely is the murky mandate usually granted a reelected president. This time, paradoxically, the more the mandate, the more the stalemate: A narrower election margin could lead to more legislative results than a clear-cut GOP triumph.
A broad mandate would also produce a number of new, conservative Republican members in the House ready to insist on their ideologically oriented programs and as a consequence becoming stalemated with their more pragmatic brethren in the Senate. But a narrower mandate would result in accommodation between the Senate and a Democratic House - and, thus, more legislative achievement.
How does one get a clear mandate? It can only come to a president who scores a clear-cut win up and down the ticket. For Ronald Reagan, regardless of his own margin of victory, that requires big GOP gains in the House (30 seats or more) and at least holding even in the Senate. As Richard Nixon could attest, a personal victory is not enough. In 1972, he won by an enviable margin - an impressive 60.7 percent of the popular vote, and 520 electoral votes, 96.6 percent of the total. But his Republican Party lost two Senate seats to the Democrats and gained only a dozen House seats. The result was that people saw 1972 more as a personal defeat of Democratic nominee George McGovern. Nixon claimed a great mandate at his inauguration on Jan. 20, 1973, but Democrats in Congress answered convincingly: ''We won a mandate, too - to oppose your mandate.''
But what if Reagan in 1984 escapes the Nixon congressional verdict and racks up the kind of electoral margin combined with gains in Congress that mark an unmistakable mandate? To GOP newcomers, the gains in the House would be attributed to the right - the so-called ''opportunity society'' Republicans. These conservatives have embraced the no-tax-increase, play-down-the-deficit rhetoric of Rep. Jack Kemp and his allies. They would come into Congress calling for Reagan to use his mandate for new cuts in domestic spending and a constitutional amendment to balance the budget along with renewed concentration on abortion, chastity, and prayer in schools.
But it would be different on the other side of the Capitol. The Senate - where the Republicans in 1984 must avoid a loss of seats - would never buy the activist agenda of new conservative House Republicans. Senate Republicans, more cautious because they have been in the majority, are going to be leery of a right-wing agenda next year. With their narrow margin of control threatened in 1986 (when they have 22 seats vulnerable to only 11 for the Democrats), Senate Republicans will want to move away from controversy and from budget cuts. They will pressure the President to play down social issues and deal comprehensively with the deficit - through tax increases and defense spending slowdowns, ideas that are anathema to the New Right conservatives in the House.
Ironically, the best scenario for action in 1985 is the one with the lesser mandate for the President. Imagine that 1984 turns out for Reagan the way Eisenhower's and Nixon's reelection efforts did: A comfortable presidential victory accompanied by mixed results in Congress. In this election that might mean GOP losses of 2 to 4 seats in the Senate and GOP gains of only 5 to 15 seats in the House, resulting in a razor-thin Republican majority in the Senate and a continuation of Democratic hegemony in the House.
Under these conditions the presidential mandate would be less - but the room for presidential maneuver and action would be more. The two main groups on Capitol Hill - Senate Republicans and House Democrats - would be ripe for consensus on a deficit package. With their cherished majority in jeopardy, Senate Republicans would insist that the President find a way early to disarm the deficit time bomb before it explodes in their faces. Meanwhile, House Democrats - the key actors in their chamber - would be trapped by their own insistence during the campaign about the dangers of the deficit.
In this scenario, a bipartisan effort to come up with a comprehensive deficit reduction package - with the President acting as midwife between Senate Republicans and House Democrats - would be a realistic prospect. There is a recent precedent: after the 1982 election. Facing an equally difficult Congress and the knotty social security issue, Reagan used the cover of a bipartisan commission to spur bold action. It was the main accomplishment of his last two years.
Mandate or no, and election results notwithstanding, President Reagan may decide not to act on the deficit in 1985. He may believe Treasury Secretary Donald Regan's assertion that the problem will be erased by economic growth alone. And he may decide to ignore criticism and go full steam ahead, pressing for an activist, New Right agenda. But if Reagan decides instead to use his reelection as a springboard to act on the mounting federal deficits, he will find, paradoxically, that action is easier with less of a mandate - and perhaps with fewer Republicans in next year's 99th Congress.