AUSTIN - Texas could pick up two, perhaps three, new congressional seats following the 2020 decennial Census if current population growth continues through the decade, political and demographic experts said Thursday.

With continued growth in Texas' four major metropolitan areas, they said, the state could almost match the gains it made in political representation after the 2010 Census, when it added four seats in Congress.

The Houston metropolitan area has led the way this decade, according to Census Bureau data released Thursday, potentially positioning the area for two additional seats in fast-growing Fort Bend and Montgomery counties.

The San Antonio area likely would be at the top of the list for an additional congressional seat, as well, said state demographer and University of Texas at San Antonio professor Lloyd Potter.

All told, the state's largest metro areas - anchored in Houston, Dallas-Fort Worth, Austin and San Antonio - added about 400,000 people last year, more than any other state in the country.

Hard to gerrymander

The greater Houston area, which includes The Woodlands and Sugar Land, added about 159,000 residents between July 2014 and July 2015, while the second-fastest-growing Texas metro area, Dallas-Fort Worth-Arlington, saw an increase of 145,000.

The state's population growth was led by Latinos in the last decade, Potter said, a trend that has accelerated.

"I can see areas that, maybe historically, were largely non-Hispanic white shifting and becoming more integrated in terms of having people of Hispanic descent, Asian and even African-American in them," Potter said.

Under those circumstances, it could become increasingly difficult for Republicans, who will control the state legislature for the foreseeable future, to draw the new congressional and state district lines in ways that favor their party.

In the short term, given the party's firm grip on power in Texas, growth in the state will favor the GOP, but that political calculus cannot last in the long-term, according to Bob Stein, a political science professor at Rice University.

"There simply aren't enough bodies to go around to draw what we might call safe Republican districts," Stein said. "Nonetheless, I think Republicans will find a way to advantage themselves, particularly in the statehouse. But increasingly, what you're going to find is a black and Hispanic population become an obstacle to drawing districts."

Pending court cases

How the redistricting fight shakes out could well be determined by two major court challenges that have the Texas electoral system somewhat in limbo.

A San Antonio federal court still is considering a lawsuit against legislative maps drawn in 2011, and the case is expected eventually to head to the U.S. Supreme Court.

In the other case, two voters who live in rural parts of the state sued Texas, arguing the state should draw political boundaries based on the number of eligible voters or registered voters who live in the area, instead of the total number of people in the district.

The high court heard oral arguments in the case in December and is expected to issue a ruling by summer.

For nearly two decades, Texas Democrats have argued that looming demographic changes favor their party in the coming years, a position they continue to assert.

"Texas did a miserable job of drawing districts in 2011 in line with the population growth of the last decade," said Chad Dunn, an election law attorney for the Texas Democratic Party. "In my view, it's impossible for the state Legislature to crack up the Latino and African-American communities in Texas any further in such a way to prevent them from electing candidates of choice."

Republican redistricting plans that helped the party in recent years are about to hit a wall, he said.

"The low-hanging and the mid-hanging fruit has already been picked. It's going to take a jump of Olympic proportions to continue denying minority American Texans in these new Congressional districts."

Who benefits?

Republican Party of Texas leaders reject any assertion that a population boom among Latinos and African-Americans largely will benefit the Democratic Party.

They point to state elections in the last decade that show Republican candidates winning a plurality or near-plurality of Latino voters in various contests, particularly U.S. Sen. John Cornyn's 2014 re-election campaign, in which he bested his Democratic opponent among those voters.

"There is no conclusion Democrats can hang their hat on that they're going to win these new voters," said Tom Mechler, the state Republican Party's chairman, adding that under his leadership the party has prioritized minority outreach.

In addition to trying to win over native Texas voters in the fast-growing areas of the state, GOP leaders argue that the population explosion in the state's metro areas is the product of new residents who have left states governed by Democratic majorities.

"It appears to us that these people are moving from high-tax states, from Democratic states," he said. "It's reasonable to conclude that they're leaving for a Republican state."