The racial tensions in Houston may be a sign of trouble to come throughout the sun belt. After decades of struggle, blacks have finally achieved some measure of political clout, and don’t want to give it up. Now Hispanics are demanding their share of political representation. The reigning assumption seems to be that the nation’s two largest minorities will have to duke it out, while white control remains intact. The 1990 census has added urgency to Latino aspirations. Projections suggest that Hispanics account for at least 25 percent of Houston’s population. Some forecasters believe that Hispanics may pass blacks (now about 30 percent of Houston) in this decade. “Our population has quadrupled in size in some areas over the last decade,” says Ben Reyes, Houston’s sole Hispanic councilman. “We are not going to wait another 10 years.”

For the moment, the Robinson seat will almost certainly remain black. In Houston, as in much of the Southwest, blacks are better organized politically than Latinos. They register in higher numbers (pollsters believe that Houston blacks account for at least 30 percent of the vote in municipal elections, Hispanics only 5 to 10 percent) and tend to vote as a block. Because the black population is concentrated in a few areas of the city, while Hispanic neighborhoods are scattered throughout, it is easier to draw “black” electoral districts.

Hispanic politicians in Houston and elsewhere in the sun belt are devising strategies to increase their piece of the pie. While national attention focuses on congressional redistricting, equally important changes will be taking place on the local and state levels: anticipating big census gains, Latino leaders are planning to challenge city-council and school-board elections in an effort to win more seats. Houston attorney Frumencio Reyes has drafted a lawsuit, to be filed in federal court this month, which seeks to revamp political representation in the city. Instead of the current city-council system, which consists of the mayor, five at-large members and nine district representatives, the suit calls for a 22-district plan - with three Hispanic districts.

Given the community’s relative lack of political involvement, Hispanic grass-roots organizers are struggling to mobilize their own forces for the good fight. One dramatic gambit: a fast by leaders like Castillo aimed at inspiring Hispanics to register to vote. The effort has brought together longtime Latino rivals. But the animus between them and Houston blacks is likely to worsen. “We can’t and won’t avoid pitting minority against minority,” says Ben Reyes. “This is not about me being racist toward blacks or blacks being racist toward me. This is about power. It’s our turn.”