LOUISIANA has cooked up another political jambalaya.The Bayou State's eccentric "nonpartisan" political primary has pushed a couple of vulnerable targets into the coming runoff election for governor. Brushed aside in what came down to a three-man race was Gov. Charles "Buddy" Roemer, who failed to sell the legislature and the electorate on what many observers felt was a reasonable blueprint for addressing the state's fiscal and social problems. Voters are to choose Nov. 16 between Democrat Edwin Edwards, who has served three rambunctious previous terms as governor, and Republican David Duke, a former Ku Klux Klan leader and former American Nazi Party adherent. At this point it appears that a majority of Louisiana voters may have been mousetrapped by a peculiar balloting procedure. In a field of 12 - yes, 12 - the top three drew 93 percent of the vote. Mr. Edwards got 34 percent, Mr. Duke 32, and Mr. Roemer 27. Despite his rational and essentially achievable program for lifting Louisiana out of the economic slough, Governor Roemer failed to convince fellow Louisianans. A graduate of Harvard Business School, he projected the image of a hard-nosed chief executive rather than a political shepherd. He tried to bulldoze Louisianans out of venerable and outworn concepts of the relationship between a government and its constituents. It must also be noted that Roemer did not defeat Edwards in the 1987 election. Edwards, hurt by two federal trials although he was acquitted in both, simply walked away from a runoff. The new governor never had a clear mandate. Putting aside the bizarre aspects of the situation, what does the conscientious - and, we would hope, unprejudiced - Louisiana voter do? Even without his far right-wing baggage, Duke, with his simplistic theories, hardly seems the kind of seasoned leader Louisiana needs at this point. Better to hope that a somewhat chastened, reform-bent Edwards will have the opportunity to use his considerable skill to restore the faith of a Louisiana populace that now needs, most of all, enlightened leadership.