Houston is a major world port; it has more restaurants per capita than just about any city, and those restaraunts are affordable; because of the massive energy, health research, and tech sectors, people from all over the world come to Houston to do business. We have our share of illegals, but so does every other city in Texas.
Harris County provides 1/3 of the GOP vote. On the whole Dallas is more liberal politically.
The liberal slant of Dallas County is offset quite nicely by the arch conservatism of Collin County.
Its like ying and yang.
Collin County is per capita the MOST conservative county in the State of Texas.
The Republican primary, in Collin County, IS the election. The Democrat candidates usually just call in the morning on election day in November, to concede, and go back to bed.