Immigration law experts have sent a letter to the White House reassuring President Barack Obama that he has the legal authority to issue executive orders on the immigration crisis.

The letter, written by 136 law professors from 32 states, Washington, D.C., and Puerto Rico, said they have reached the same conclusion and explained how potential executive action by Obama will be as "equally lawful" as the implementation of the Deferred Action for Childhood Arrivals program.

"As part of the administration's legal team that ironed out the details of DACA, I can personally attest that we took pains to make sure the program meticulously satisfied every conceivable legal requirement," said Stephen Legomsky, professor at the Washington University School of Law, who was also a former chief counsel for the U.S. Citizenship and Immigration Services.

The letter informs Obama that he has the legal authority to use "prosecutorial discretion" as a method to protect an individual or group from deportation. The letter noted "prosecutorial discretion" is the Department of Homeland Security's ability to decide how immigration laws should be implemented. The letter also recognized that U.S. immigration agencies have a "long history" of utilizing "prosecutorial discretion" on both a case-by-case and group basis.

According to Penn State Law's Samuel Weiss Faculty Scholar Shoba Sivaprasad Wadhia, Obama has the same legal authority as several previous presidential administrations. The letter also emphasized previous presidents, from both political parties, have used the same legal authority to prevent groups of immigrants from deportation.

Wadhia said, "Historically, this policy has been premised on the twin policy goals of managing limited resources and shielding people with compelling situations from removal." 

A statement from the American Immigration Council acknowledged the letter is the second time law professors collaborated on a message to Obama. In 2012, law professors supported the legal argument to expand administrative relief, a concept that would help establish DACA, which granted temporary stays to undocumented immigrant youths meeting specific eligibility requirements.

According to the USCIS, over 553,000 DACA requests have been approved. Most of the applicants are from Latin American countries, notably Mexico, El Salvador, Guatemala and Honduras. Applicants also hail from countries outside Latin America, such as India, Pakistan and South Korea.

"First, the president has the legal authority, exercising his discretion as the nation's top immigration prosecutor, to establish enforcement priorities," said Hiroshi Motomura, professor at UCLA School of Law. "Second, the president's lawful discretion includes the authority to set up an orderly system, modeled on DACA, for granting temporary relief from deportation."

Obama said he is willing to issue an executive order because of inaction by Congress. Obama said he's waiting on recommendations and proper legal methods from the Departments of Justice and Homeland Security before announcing any action. In August, White House Press Secretary Josh Earnest previously stated a presidential executive action could come in September, but reports suggest a delay until November is likely due to uncertain re-election odds for Senate Democrats.