I was hunting around for this San Antonio article you referenced, and came across this one, where the Castro brothers claim that Texas will go blue in 8-10 years, but are rebutted with this: Hispanics don't vote.
quote: San Antonio Express-News
“I just wanted to throw cold water on everything you have all said,” responded Nina Perales, vice president of Mexican American Legal Defense and Educational Fund. Perales warned that if Latinos in Texas do not mobilize to increase voter registration and turnout, there will be no such change.
Perales continued to underscore the bottom line: “We're losing ground,” she said. “We have more U.S. citizen Latinos turning 18 every day than are getting registered. The gap between eligible and registered in the Latino community is widening, not narrowing.”
Also, there's the factor that a significant amount of Hispanics in Texas are noncitizens and ineligible to vote.
For instance, the Irving school district (a Dallas suburb) is heavily Hispanic, but cannot elect a Hispanic to the board because
1. they don't vote
2. they (the courts) couldn't draw a map that gerrymandered enough citizens eligible to vote to make a difference. LINK
ETA: If I may add another example which just came to me.
There was a U.S. Congressional district drawn up in DFW that was supposed to elect a Hispanic, but instead, a black candidate won.
quote: Dallas Morning News
For the first time since his congressional run began, Domingo Garcia said Thursday that his ethnicity is a top reason voters should support him in the race for the area’s newest U.S. House seat.
“The district was created as a Hispanic seat. It’s 66 Hispanic and 17 percent African-American,” Garcia said.
As I say, he lost.
This post was edited on 1/20 at 9:39 pm