The state’s boom in population — census data in 2010 showed it had grown by 20.6 percent since 2000 — gave Texas four new seats in Congress, for a total of 36. The Legislature-drawn maps would give Democrats fewer Congressional and State House seats than the maps created by the three-judge panel, which could deliver to Democrats as many as four additional seats in Congress and about a dozen in the State House. Several minority groups and lawmakers argued that the Legislature’s maps did not reflect growth in the state’s Hispanic and black populations, and violated minority voting rights laws. Attorney General Greg Abbott and Republican leaders maintain that no court has found the Legislature’s maps to violate any law and say that the federal panel in San Antonio exceeded its authority in issuing its own maps.

“This is all about the changing demographics in Texas and what that means for partisan politics,” said Mark P. Jones, a political science professor at Rice University in Houston. “In Texas, most of the growth in population that has resulted in Texas’s four additional Congressional seats is a result of a growth of the Hispanic population. But this Hispanic population generally votes Democratic. At least a segment of the Republican Party is trying to keep the growing Hispanic electorate from negatively impacting their power in the state for as long as possible.”

Gov. Rick Perry signed the Legislature’s maps into law in June and July. Minority groups sued the state in federal court in San Antonio, charging that those maps discriminated against minorities.

Image Attorney General Greg Abbott of Texas. Credit... Bob Daemmrich for The Texas Tribune

But Texas and other states with a history of racial discrimination cannot put new maps in place without federal approval. So, the state had asked a federal court in Washington to approve the Legislature-drawn maps, but the court refused, prompting the San Antonio judicial panel to create an interim map so that the elections could proceed. The federal judges in Washington, in their ruling last month, faulted the state for using an improper methodology to determine whether the Legislature’s maps hurt minority representation.

Meanwhile, the Justice Department, whose civil rights division also found the state’s maps to discriminate against minorities, has become a central figure in the dispute. The Texas attorney general accused it this month of delaying the federal-approval process in an effort to have the court-drawn maps imposed, a claim the agency denies.

For the most part, reaction to the Supreme Court’s decision on Friday to take up the matter tracked along party lines, with Democrats expressing some disappointment and Republicans feeling pleased. State Representative Trey Martinez Fischer, a San Antonio Democrat who is the chairman of the Mexican-American Legislative Caucus, one of the groups that sued the state over redistricting, said in a statement that they were “deeply concerned about the potential disruption of the 2012 election schedule.”