Mikhail Gorbachev has won a mandate to do the impossible: preserve the Soviet empire while renewing it; maintain central control over republics that are sovereign and equal; and guarantee individual rights his Communist Party has never respected.

The overwhelming "yes" vote in the Soviet Union's first, ambiguously worded referendum comes after a one-sided media campaign. It is plain, however, that Gorbachev's victory is qualified in profound ways.Six republics refused to hold the referendum at all. These include the three Baltic states. To deliver national unity, Gorbachev must bring these republics back into the fold. It is unlikely that can be done without massive use of force, something Gorbachev has so far shunned.

And in the biggest republic, sprawling Russia with its 150 million people, Gorbachev's archrival Boris Yeltsin won a countervailing victory.

Voters endorsed direct election of the president of the Russian Republic. Yeltsin - the current president, elected by Russia's parliament - would win such an election, embarrassing Gorbachev who was never chosen by the voters.

Yeltsin bears the standard for those who say the union must be rebuilt from the bottom up, as a voluntary federation governed by democratic principles.

The two men are headed for a showdown March 28, when the Russian parliament will consider a no-confidence vote in Yeltsin for demanding that Gorbachev resign as Soviet president.

Whatever becomes of Yeltsin and of the Baltics and the other renegade republics, Gorbachev's real problem is that he cannot cure the Soviet Union's ills.

He is retreating from his political liberalization, muzzling the press. His economic ineptitude is rooted in his Leninist convictions.

The election reflected Soviet citizens' yearning for both order and renewal. It shed no light on whether they will move toward either one.