I believe part of the problem in Texas with property taxes is that there is no state income tax...so they get it where they can. Same story everywhere...
Having said that (and without doubt, a bunch of people will jump in screaming about that statement), the point you made can be generalized to this: the Caudillo's of Mexico have figured out that if they can just shove enough warm bodies into the U.S., they can vote to take the country away from us, one lousy tax sale at a time. All with the help of leftists who believe that the poor of Mexico deserve our wealth and property, and we don't.
This is demonstrated here in Northern California in a very concrete way every day. The leftists in the government here routinely vote to erect public housing for 'low income' people (wink wink. Guess who), no development can go forward without a holdout section for 'low income' renters/subsidized owners, and areas that used to be single family dwellings are routinely bought up using county money to be converted to 'high density low income housing'...once again, to be subsidized (rents at less than 1/4 market, typically).
William Hawkins painted the whole picture 12 years ago in his book Importing Revolution: Open Borders and the Radical Agenda. It amazes me that he nailed the program so well, and terrifies me to see it unfolding as he predicted, since like you, I'm at ground zero of this disaster.
BTTT