Armed with new powers from the Voting Rights Act, Hispanic organizations have scored a string of legal victories in overturning discriminatory at-large voting systems in cities and school districts.

Encouraged by these victories, the groups recently filed five more lawsuits against jurisdictions in three Texas cities. They expect to file another suit soon, and have urged 10 more cities in Texas to convert at-large local voting systems into ones that include single-member districts.

In addition, leaders of the groups responsible for the lawsuits say cities once hostile to changes in their election systems have begun to indicate a willingness to seek negotiated settlements to avoid long and often costly court battles.

The anticipated effect of these actions is an increase in Hispanic representation in local governments in the Southwest, and as a result of that, a further increase in voter registration and turnout, Hispanic leaders said.

Under at-large systems, minorities have difficulty winning elections because they often are less than a majority of a city's overall population.

With voting often polarized along ethnic lines, the strength of their vote is diluted. With single-member districts, minorities are able to win seats in areas of town where they constitute a majority population.

In a number of Texas jurisdictions now facing legal action, Mexican Americans make up a third to three-fifths of the population, yet have elected only a handful of representatives to city councils or school boards, according to research cited by lawyers for the Mexican American Legal Defense and Education Fund.

Hispanic leaders say the recent victories are a direct result of a newly strengthened section of the Voting Rights Act, enacted amid great controversy by Congress last summer.

As amended, Section 2 requires that challenges to these at-large systems prove only that the systems have had the effect of discriminating against minorities, not the more difficult proof of intent to discriminate.

The change in the law superseded a 1980 Supreme Court ruling that challenges to at-large voting systems must prove that the systems were erected intentionally to deny minorities the opportunity to win elections.

"Prior to the amendment, the law discouraged us from pursuing litigation," said Joaquin Avila, MALDEF's president and general counsel. "We just simply did not file. The passage of Section 2 . . . has provided us with a very powerful tool."

Since the passage of the amendment last year, Hispanic organizations have concentrated their efforts in Texas, and have won legal victories or negotiated settlements in at least six Texas jurisdictions, including Lockhart, where the Supreme Court earlier had refused to order election changes under the terms of the old Voting Rights Act.

"Texas is where the most egregious problems have been documented," Avila said. He called the state "our Mississippi," comparing voting systems that have discriminated against Hispanics in Texas to those that discriminated against blacks in Mississippi.

But the Hispanic groups, which also include Texas Rural Legal Aid and the Southwest Voter Registration Education Project, said they intend to attempt to document abuses in California and elsewhere. Based on that research, they said, they will begin to bring lawsuits in those other states.

Breakthroughs in Texas came in actions affecting Corpus Christi, Lockhart and Lubbock. In March, U.S. District Court Judge George Kazen ruled that the Corpus Christi at-large system for electing city council members violated the amended Voting Rights Act and ordered the city to prepare a new plan.

It since has adopted a mixed system that includes four members elected at-large and five elected by districts.

The city has accepted the decision with only a few complaints, but there are signs of resentment toward the courts. "Oh boy," said city attorney Bruce Aycock. "Shades of Reconstruction."

Hispanic lawyers said the Corpus Christi decision had a powerful effect on other cities.

The Lockhart case was in litigation at the time that the Voting Rights Act was amended, and the city was upheld by the Supreme Court in its argument that a new city charter did not represent discrimination against minorities. But the Supreme Court sent the case back to the U.S. District Court to consider the issue in light of the new Section 2 provision.

Shortly after the decision in the Corpus Christi case, Lockhart agreed to a settlement with the Hispanics who were challenging the city's system. A lawyer in the case has been quoted as saying the reason for the change in attitude was the new Section 2.

The Lubbock case, although it is expected to be appealed to the 5th U.S. Circuit Court of Appeals, has had a ripple effect on other jurisdictions, according to Rolando Rios of the Southwest Voter Registration project. He said that five jurisdictions in west Texas had indicated a desire to begin negotiations since a federal district court ruling that the Lubbock city council system was discriminatory.

"Before the change in Section 2 and the Corpus Christi decision, we would go into a jurisdiction and the atmosphere was hostile," said Jose Garza, a MALDEF lawyer in San Antonio. "Now we're in a new era."

Last week MALDEF filed suits affecting city council systems in Pecos and Port Lavaca, and school districts in New Braunfels, Port Lavaca and Pecos.