The map of congressional districts drawn up by Texas elected officials just after the 2010 census was not only illegitimate and illegal, but designed with a “discriminatory purpose” that aimed to limit the influence of Latino voters, a federal court in Washington, D.C. ruled Tuesday.

The ruling will not affect the districts in which people vote for the November election, though Texas will likely have to redraw its district maps by 2014, as the heated political and legal wrangling over those maps continues. The sharply worded ruling provided a detailed account of Texas officials' plans to draw districts for four new congressional seats created by the state’s booming Latino population that were almost certain to elect Congress members preferred by white Republican voters. And it's a ruling that should serve as a cautionary tale, according to voting rights advocates.

“For other states thinking of doing anything to dilute the [power] of their minority voters or their fast-growing minority populations, this is not just a warning,” said Nina Perales, vice president of litigation at the Mexican American Legal Defense Fund (MALDEF), a civil rights organization based in San Antonio. “This is a warning in the strongest terms.”

MALDEF sued the state in federal court on behalf of a group of voting and civil rights groups.

Texas Attorney General Greg Abbott, a Republican, said that the state will appeal Tuesday’s ruling.

"Today's decision extends the Voting Rights Act beyond the limits intended by Congress and beyond the boundaries imposed by the Constitution," Abbott said in a statement. "The Attorney General's Office will continue defending the maps enacted by the Texas Legislature and will immediately take steps to appeal this flawed decision to the U.S. Supreme Court."

Outside of court, the state's Republican-controlled legislature will have two options when they return to session in January. They can attempt to draw a new map, or a San Antonio-based federal court will likely take up the case if they opt not to act. That court, along with the U.S. Supreme Court, played a role in prompting Texas to adopt an compromise interim plan used for this year's primary elections.

At issue are two critical aspects of the American electoral system.

The first is congressional reapportionment. Every 10 years, after the Census, the data gathered is used to assign seats in Congress to growing states and remove them from those with shrinking populations. Once that process concludes, state authorities draw new district maps.

Second, because of Texas' history of discrimination against minority voters, it belongs to a group of mostly Southern states that must seek federal approval for any maps the legislature develops. These states must also create “opportunity zones,” districts designed to include a majority of minority voters.

The idea is that a candidate -– whether white, black or Latino –- elected by minority voters will represent these voters' interests and needs or face the risk of losing their seat in the next election. So, states' attempts to eliminate opportunity districts or mitigate their impact on elections are often declared illegal, voting rights experts told The Huffington Post in May.

After Texas won four new seats in the 2010 reapportionment process -- something which was due almost entirely to growth in the state's Latino population -- its state legislature attempted to circumvent the Voting Rights Act. In a November 2010 email obtained by the Mexican American Legal Defense Fund and presented as evidence in court, a Texas legislative staffer suggested drafting new districts by identifying communities with a large number of voters with “Spanish” surnames and low voter turnout, then lumping them together into an opportunity district.

Staffers drawing the state’s new congressional districts pushed areas with a large number of very active Latino voters into mostly Republican and non-Hispanic white districts. With these maps in place, the impact of the more active and largely Democratic-leaning Latino voters would be minimized and Republicans in these areas could be safely reelected. With the new districts in place, it became highly unlikely that candidates preferred by minority voters would hold any of the state’s new congressional seats.

In the wake of the ruling, it is possible that state officials will elect to draw a congressional district map that is fair, legal and reflects the state’s changing demographics. If not, MALDEF and other voting and civil rights groups are ready, Perales said.

“It is true that methods of discrimination become more sophisticated over time but ... we are up to the task of spotting it,” Perales said.