AUSTIN, Texas (Reuters) - Texas should be playing a role in Republican politics this year as big as, well, Texas.
The fast-growing state - the most populous by far in the Republican column - has four new seats in the U.S. House of Representatives, a big U.S. Senate race and more than a 10th of the delegates who will choose the party's presidential nominee.
But a racially tinged dispute over redrawing its congressional districts has delayed the Texas primary by almost three months, complicated the U.S. Senate and House contests and altered the race for the White House.
A San Antonio court pushed Texas' primary back to May 29 from March 6 after complaints that a new electoral map drawn by Republicans violated the federal Voting Rights Act by diluting the voting power of blacks and Latinos.
Three of Texas' four new U.S. House seats were created in areas dominated by whites, even though Hispanics and blacks accounted for 90 percent of Texas' population growth since 2000.
The battle sets white Republicans, who have firmly established political control in Texas within the past decade, against rising and strongly Democratic Hispanic and black populations, whose leaders argue that they are being unfairly denied an equal voice in state politics.
The stakes are high both for 2012, when the White House and control of the U.S. Congress are up for grabs, and longer term, when a rapidly growing Hispanic population is expected eventually to disadvantage Republicans and benefit Democrats.
"Republicans can work that racial solidarity thing for a while, but in the end, they've got to do better than 35 percent of the Hispanic vote or their election prospects are not great," said Cal Jillson, a political science professor at Southern Methodist University in Dallas.
States with a history of minority voting rights violations must obtain pre-clearance from either the U.S. Department of Justice or the federal court in Washington, D.C., before they can use new maps. The new voter map in Florida, another fast-growing southern state, has also been subject to legal wrangling this year.
Non-Hispanic whites already account for a minority of Texas' residents, with 45 percent of the population. The state is 38 percent Latino and 12 percent black, numbers expected to continue to rise.
President Barack Obama lost Texas by 11-percentage points in 2008. He got only 26 percent of the white vote, but was backed by 63 percent of Hispanics and 98 percent of blacks, fueling talk that it will not be long before Republican red Texas turns purple, if not Democratic blue.
"We sort of feel like we have the wind at our backs," said Anthony Gutierrez, deputy executive director of the Texas Democratic Party.
Democrats have won Texas in only three of the last 15 presidential elections. The party has not won a statewide election since 1994, and Republicans cemented their control of the state with huge victories in the 2010 midterms.
But even Republicans acknowledge that changing demographics mean the party must appeal to Hispanics to hold onto power beyond the next few years. Latinos in Texas generally vote Democratic by a 2-to-1 margin, which won't be helped by a redistricting fight seen as a battle to maintain white control.
"It is obviously a high-risk strategy in a state that is increasingly Hispanic," said Michael Li, a Dallas-based election law lawyer who runs the blog "Texas Redistricting." Li is not involved in the redistricting fight.
The redistricting mess has already affected the 2012 presidential race, notably the hopes of Mitt Romney, who may have done well in the Texas primary if it had taken place on Super Tuesday - March 6 - as originally scheduled.
Texas would have been the biggest prize up for grabs on Super Tuesday, when 10 other states held primaries and caucuses.
Romney, with far more money and a bigger campaign organization than rivals Rick Santorum and Newt Gingrich, was best placed to compete in so many states at once. Texas alone has 20 media markets, meaning statewide advertising can cost millions.
Winning or putting in a good showing in Texas would have boosted Romney. The state's 155 delegates, awarded proportionally, are a huge chunk of the 1,144 needed to become the nominee.
A strong performance on Super Tuesday also would have given Romney a badly needed breakthrough in the heart of southern Republican conservatism, weakening Santorum and perhaps cutting short what has become a protracted nomination fight.
Instead, Romney has been a weak front-runner and Santorum, a former Pennsylvania senator best known for strong religious conservatism, has been winning over the party's right wing.
"It (a March 6 Texas primary) would have changed a lot of things. It would have changed the entire complexion of Super Tuesday," said Matt Mackowiak, an Austin-based Republican strategist, especially with Santorum and Gingrich both vying for the support of the most conservative Texans.
"I suspect if the field was split and if Santorum and Gingrich hadn't had $5 million or $3 million to spend, then Romney probably would have won Texas on March 6," he said.
With Texas now one of the last states to vote, the nominee could be chosen by May 29. Even if it isn't, Santorum is now considered more likely to take Texas, thanks to improving fund-raising and his solidified position as the conservative alternative to Romney.
"Romney starts with a significant disadvantage in terms of public opinion," said Jim Henson, director of the Texas Politics Project at the University of Texas at Austin, although he added that Romney's big campaign war chest means that he could spend heavily in Texas to target clusters of mainstream conservatives in major media markets.
A Wilson Perkins Allen Opinion Research poll last week showed Santorum eight percentage points ahead of Romney among likely Republican primary voters in Texas. Santorum was at 35 percent to 27 percent for Romney.
Gingrich was at 20 percent and Ron Paul, a Texas congressman lagging in most polls, was at 8 percent.
The redistricting mess is affecting races down the ticket as well, with many voters not sure where they are registered and many candidates unsure of where they should run or raise money while the court fight has continued.
"I can look around the state and see the confusion in the eyes of the average voter," said Chris Elam, communications director for the state Republican party. Some 100 Republicans alone have applied to run for the 36 House seats, he said.
The interim map is expected to stand, but there is a chance it could be changed again by the Washington court.
The May 29 date is after schools close for the summer, leading to worries that turnout will be low, which often leads to unpredictable results.
The race to replace retiring Republican Senator Kay Bailey Hutchison has been most affected by the upheaval. Lieutenant Governor David Dewhurst has been favored to replace Hutchison, because of his statewide name recognition and fundraising prowess.
But the long delay has given opponents, especially Tea Party favorite Ted Cruz, time to raise money and their profiles. Former Dallas Mayor Tom Leppert and Craig James, a one-time television sports analyst, are also in the race.
If no one wins a majority on May 29, state law mandates a runoff vote on July 31, the heart of the hot Texas summer when an even smaller turnout would be expected.
Editing by Alistair Bell and Cynthia Osterman