Sooner than you might think:
Immigration from Mexico only partly accounts for the change [to a non-white majority state]. More than a million Americans have moved to Texas in the past decade, many from traditionally Democratic states. More than three hundred and fifty thousand Californians have arrived in the past five years; since 2005, over a hundred thousand Louisianans permanently relocated to Texas, mostly in Houston, after Hurricane Katrina. The population is also skewing younger, which means more Democratic.
But [Steve Munisteri, chairman of the Republican Party of Texas,] is more preoccupied by the racial and ethnic changes.
He turned to a chart showing Texas’s population by ethnic group over the next few decades. A red line, representing the white population, plunged from almost fifty-five per cent, in 2000, to almost twenty-five per cent, in 2040; a blue line, the Hispanic population, climbed from thirty-two per cent to almost sixty per cent during the same period. He pointed to the spot where the two lines crossed, as if it augured a potential apocalypse. "This shows when Hispanics will become the largest group in the state," he said. "That’s somewhere in 2014. We’re almost at 2013!" He added, "You cannot have a situation with the Hispanic community that we’ve had for forty years with the African-American community, where it’s a bloc of votes that you almost write off. You can’t do that with a group of citizens that are going to compose a majority of this state by 2020, and which will be a plurality of this state in about a year and a half."
(Map: a cartogram of the US and its 2012 red and blue counties by population. By Mark Newman of the University of Michigan. You will notice that Florida has not been circumcized in this rendition.)