PHOENIX - The state has hired a former immigration official as an expert in its bid to deny driver's licenses to thousands of Arizona "dreamers" eligible for a deferred-action program.

In documents filed in U.S. District Court here, attorney Robert Brown acknowledged the directive by the Obama administration permits some individuals in this country illegally to stay. It even provides papers allowing those in the program to work legally.

But Brown, a former district director for what at the time was the Immigration and Naturalization Service, says nothing in the Obama administration's order authorizes these individuals to be in the country.

Potentially more significant for the legal fight now playing out in court, Brown contends those in the administration's program, formally known as Deferred Action for Childhood Arrivals, are not the same as those in other deferred-action programs - people to whom the state has given licenses.

While the new deferred- action program is similar to others in that it gives federal immigration officials discretion to decide who to pursue, Brown said said the key difference is that every other kind of deferred action is specifically authorized by Congress, not just an administrative decision by the president.

Those distinctions are critical in the fight by Gov. Jan Brewer to convince a federal judge that Arizona is not required to provide licenses.

A 1996 state law requires applicants to show their presence in this country is "authorized by federal law." If Judge David Campbell can be convinced those in the program are not "authorized," it undermines the lawsuit filed on behalf of those who contend Brewer and her administration are denying them licenses illegally.

"Filing for DACA and a subsequent grant (or denial) of DACA does not confer lawful status and does not change the fact that the foreign national is removable under the Immigration and Nationality Act," Brown wrote in his statement to the court.

"Likewise, there is no federal law that authorizes a DACA recipient's presence," he continued. "Quite the contrary, by deferring removal, the executive has decided to not enforce federal immigration law as to a DACA recipient."

Campbell already has rejected a request for an immediate directive to provide licenses, opting instead to let the case simply go to trial.

But the judge suggested he believes the challengers could succeed in their claim based on an equal-protection argument because Arizona does provide licenses to others in different deferred-action programs.

"Defendants have identified nothing ... to suggest that DACA recipients are somehow less authorized to be present in the United States than are other deferred-action recipients," Campbell wrote. "All deferred-action recipients are permitted to remain in the country without removal for a temporary period of time and the Employment Authorization Documents held by those recipients appear to be valid only for a temporary period."

It would be a constitutional violation for the state to provide disparate treatment to individuals who are in similar situations.

But Brown argues their situations are not totally similar.

For example, he said those seeking asylum or refugee status, as authorized under the Immigration and Nationality Act, can be allowed to remain in this country. And they are among the groups which have been granted Arizona licenses.

Similarly, Brown said Congress approved the Violence Against Women Act, which he said is based on "express congressional intent" to allow victims of domestic violence to remain and even provides a path to legal status.

"DACA, on the other hand, provides relief to a population of foreign nationals to whom Congress has repeatedly refused to grant status or another other basis to remain in the United States, and provides no pathway to status," Brown wrote. "It is merely an enforcement decision, not a federal law."

Hanging in the balance is the ability of Arizonans accepted into the program to be able to drive, including to school and to the jobs that the Obama administration has said they can have.

At last count, more than 539,000 applications for deferred action had been received across the country, including close to 18,500 from Arizona. U.S. Citizenship and Immigration Services has approved 365,000 requests, nearly 13,700 of them from Arizona residents, including the five plaintiffs challenging Brewer's action.

It has been estimated that about 80,000 Arizonans could qualify for the program, which covers those in the country illegally who arrived before age 18, were not yet 30 when it was announced and are not guilty of felonies and certain misdemeanors.

"Filing for DACA and a subsequent grant (or denial) of DACA does not confer lawful status and does not change the fact that the foreign national is removable under the Immigration and Nationality Act."

Attorney Robert Brown, in his statement to the court