There are several millions of Hispanics in Texas whose families have been here since Independence -- and before -- who would sharply disagree with your conclusion.
There were many Hispanics inside the Alamo...and at Washington-on-the-Brazos.
Your description may be accurate for the late arriving illegals, but it's not accurate for the bulk of legal Hispanics.
We just had an election, 71% of “legal” Hispanics voted for Obama’s second term.
Hispanic voters are Legal (heck they're citizens) and they vote Democratic.
It's not illegals who make those Texas border counties democrat strongholds.
A majority of legal Hispanics, at least until the third generation (and I don’t believe they have polled further) are on some form of welfare—and of course they all qualify for affirmative action.