The problem today is that most times the white vote is split 50/50. Then the minority block (blacks - 97% democrat) come into play.
The Hispanic population in Texas is mostly Mexican or of Mexican descent, unlike Florida, where Jeb and Marco are from. “Cuban-American” Ted Cruz won over 40% of the Hispanic vote 3 years ago. All else being equal, do you know what you call a Republican who can garner 40% of the Latino vote in a national election?