Hidden in the haze of the petrochemical plants and beyond the seemingly endless traffic jams, a Texas city has grown so large that it is poised to pass Chicago as the third biggest in the United States in the next decade.

Houston has been one of the fastest-growing U.S. cities for years, fueled by an energy industry that provided the backbone of the economy, low taxes and prospects of employment that have attracted job seekers.

But Houston also embodies the new, urban Texas, where political views have been drifting to the left, diversity is being embraced and newer residents are just as likely to drive a hybrid as a pickup truck.

Houston's move is also indicative of demographic shifts unfolding in the United States that will increase the population and political clout of the Lone Star State over the next several decades.

Within eight to 10 years, Houston is forecast by demographers in the two states to pass Chicago, which has seen its population decline for years, as the third-largest city.

Houston is projected to have population of 2.54 million to 2.7 million by 2025 while Chicago will be at 2.5 million, according to official data from both states provided for their health departments. New York and Los Angeles are safe at one and two respectively.

Houston has long been associated with the risk takers in the oil industry and more recently as one of the better cities to find a job.

"Texas has a long tradition, and Houston has it in spades, that we are not so much interested in where you are from. We want to know what you can do," Houston Mayor Annise Parker said in an interview with Reuters.

Chicago officials were not immediately available for comment.

Apart from domestic migration, about one in five Houstonians is foreign born and more than 90 languages are spoken in the city.