Some wise man cautioned that we should be careful what we pray for; we just might get it.

The wise-guy southern Democrats who devised Super Tuesday might be reflecting on that advice.

They prayed for a miracle that would give southerners a bigger voice in the presidential nominating process, that would keep liberals from moving the party toward the middle and thereby halt the defection of conservative Democrats to the GOP. And, not to be racist about it, it would be nice if the miracle could also alter the role of black voters, whose votes the party needed but whose influence it feared.

They got Super Tuesday. And to what effect? They wanted to isolate the more liberal candidates and forestall the possibility that the party would nominate an unelectable liberal like Walter Mondale, who garnered just 38 percent of the southern vote in 1984. But as Ed Brown of the Voter Education Project notes, the practical effect of Super Tuesday may be to isolate black voters.

As a result, black voters -- through the candidacy of Jesse Jackson -- may wield more influence than ever at the nominating convention.

"What is happening," says Brown, "is that the white candidates will be vying with each other for the white vote" in the 20, mostly southern, Super Tuesday states, while "conceding the black vote to Jesse."

There are two reasons for this. One is the calculation that Jackson has a lock on the black vote in any case. The other is that any serious attempt by a white candidate to appeal to black voters could wind up costing white votes.

As Brown sees it, the other candidates will compete for black voters only in the most benign way, primarily by trying not to offend them. "Basically, they will let Jesse have the black vote and then try to deal with him at the convention."

If it gets that far. Eddie Williams, president of the Joint Center for Political Studies, says it is possible that Super Tuesday, rather than increasing the leverage of southern Democrats, may actually reduce their influence by fragmenting the vote along racial lines. If that happens, he says, it may shift the major nominating influence to the states of the North and West.

On the other hand, if there is no clear-cut front-runner by convention time, Jackson, who figures to have amassed several hundred delegates, may find himself in the role of king maker.

A lot, of course, depends on factors that cannot be predicted. A strong Super Tuesday showing by Richard Gephardt or Michael Dukakis, who already have done well in the early primaries, could furnish enough momentum to reduce the Jackson role. If Tennessee's Albert Gore is the big winner in the Super Tuesday primaries, he still might have difficulty shedding the notion that he is merely a regional candidate.

But suppose Jackson is able to attract enough white votes to make him the Super Tuesday winner, as the polls suggest is a real possibility. The result could be a brokered convention, with Jackson in a powerful bargaining position.

The question is: What would he bargain for?

It seems doubtful that he would be able to impose any sort of identifiable "black agenda," since to do so might deliver the election to the Republicans. The most likely outcome might be a deal for Jackson himself -- say secretary of state.

Whether the elevation of Jackson is adequate recompense for what could be unprecedented black political power is another question.

In any case, the southern Democratic state legislators who devised Super Tuesday are likely to discover that what they prayed for isn't what they wanted. The guessing here is that they will have moved the party at least somewhat to the left, diminished their influence on the nominating process and strengthened the role of black voters -- not necessarily a bad result, but clearly not what they had in mind.