There are few more politically polarizing issues of late than immigration reform, but for many in Houston, President Barack Obama‘s recent executive order on immigration is about business.

“For legal contractors it’s going to be a tremendous boom because now we have access to labor that we haven’t been able to hire,” said Stan Marek, CEO of Houston-based Marek Brothers Company Inc. and longtime proponent of immigration reform.

Many Houston business owners have depended on undocumented workers for substantial portions of their workforce and are thus continuously rolling the dice that they won’t get audited and ultimately have to dismiss enough employees to shut down their business, either temporarily or permanently, said Foster” >Charles Foster, founding partner of Houston-based immigration law firm Foster LLP.

Obama’s executive order extends temporary relief from deportation to undocumented parents of children who are U.S. citizens or lawful permanent residents, have been in U.S. for five years or more and have no criminal background. The order also expands the 2012 Deferred Action for Childhood Arrivals program, which offers unauthorized immigrants who arrived in the U.S. before turning 16 temporary relief from deportation action. The expansion eliminates the age cap for applicants and revises the cutoff arrival date from 2007 to 2010.

Nationwide, roughly 5.2 million unauthorized immigrants may be eligible for these programs, according to the Migration Policy Institute. This is also a relief for Houston’s burgeoning immigration law practices, which finally have a legal framework within which to help business owners legitimize their workforce.

“There is going to be a rush of a million-plus individuals wanting to get into the system,” Foster said.

The number of undocumented workers in Houston is hard to pin down. The Migration Policy Institute breaks down its data by state, putting Texas’ unauthorized population at nearly 1.5 million, with 80 percent born in Mexico.

The University of Texas at Austin collaborated with the Austin-based Workers Defense Project to report on issues related to employing undocumented workers. The report, released in January 2013, said roughly 50 percent of the construction workforce in Texas is undocumented. Those numbers are made more problematic when the Texas Legislature drags its feet on immigration policy.

But it’s not just workers in the construction industry. Currently, recruiting top talent from pools of international students in competitive undergraduate and graduate programs across the U.S. is fraught with regulatory difficulties, Foster said.

Suzanne Edwards covers money and law for the Houston Business Journal.