1988's Mega-Super Tuesday. Backers say Southern regional primary can steer Democratic Party farther to the right

The strategy and pace of the 1988 presidential primary season are already shifting markedly. The South is adding states to its Southern Regional Primary, or Mega-Super Tuesday -- the Southern plan to help nominate more conservative Democrats for president.

Tennessee Gov. Lamar Alexander became the latest of three governors in the past two weeks to sign bills moving their 1988 primaries to March 9, Mega-Super Tuesday. So far, seven states in the South or bordering the South are holding primaries on the same day. Three more have legislation in the works and strong support for the idea. Five others are considered likely to follow suit.

The South could be just the beginning. At least four bills have been introduced to the US House of Representatives this session, the latest last week, to promote regional primaries for the whole country.

The South is not waiting for the outcome of the House bills. Southern states, by piling up their primaries at the beginning of the season, hope to diminish the traditional role of New Hampshire and Iowa as bellwether states. Candidates will have to campaign first and longest in the South, the plan goes, where they will have to play to Southern opinion. A moderate Democrat, and perhaps a Southerner, Southerners hope, will emerge.

``It's clear that a Democrat does not win the presidency without winning the South,'' says Bill Youngblood, Democratic Party chairman for South Carolina. And the South is likely to use its greater clout under a Southern Regional Primary to swing the Democratic ticket in 1988 toward a more conservative nominee, one with a better chance of beating the Republican candidate, Mr. Youngblood says.

There is another reason for piling the region's primaries onto one date -- simplicity. A regional primary could save time and money by allowing a candidate to campaign in one region at a time.

Charles Williams, director of the Southern Legislative Conference, says of the legislators supporting the plan: ``More than anything they want to simplify it so the logistics make a little more sense.''

But while the concept gathers momentum, doubts are persistently popping up about whether a Southern Regional Primary will actually work as expected.

``At first, the notion was that you would have a single, moderate candidate scoring a regionwide success,'' says Merle Black, political science professor at the University of North Carolina.

But a lot of moderates will be competing for the Southern states, and unless one of them has a ``tremendous amount of resources,'' says Dr. Black, it is not at all certain that a single moderate will emerge. If that happens, the moderates could split the field, allowing a marginal candidate to win by a plurality.

In addition, there is the possibililty that conservative Southern Democratic voters will abandon the Democratic primaries for the Republican -- where there will also be a hot contest in 1988. This would leave the Democratic primaries to more liberal elements in the party.

The concerns are legitimate, says Tennessee Democratic chairman Richard Lodge, a proponent of the regional primary. But, he adds, ``there are always risks in politics.''

One of very few Southern Democrats to oppose the regional primary is South Carolina's member of the national party's executive committee, Don Fowler. ``The people who are mostly behind the Southern primary are psychologically in another era,'' he says. Southern primaries are now dominated instead by moderate liberals, he says, not the conservatives who now vote Republican.