A few years ago, Texas hit a demographic tipping point and became a majority-minority state, a status currently shared with Hawaii, New Mexico, and California. In the past two presidential elections--2008 and 2012--Democrat Barack Obama carried all but Texas.
Of the four most populated states in the U.S.--California, Texas, New York, Florida--Obama twice carried three out of the big four, but came nowhere near to carrying Texas.
Abby Rapoport argues in The American Prospect however, that Texas might be a potential state where the Democratic Party might become competitive.
Her article is linked below.
Abby Rapoport Examines the New Demographics of Texas and Potential Electoral Implications