Zulleth Romero was 12 when she and her mother trekked through the ovenlike Arizona desert. The two ran out of water and Romero’s mother collapsed when she reached the highway, where a smuggler picked them up and transported them to Phoenix. Both survived, and the girl, now 18, recently graduated with honors from a Phoenix-area high school.

On Wednesday, like many of the nation’s 1.7 million young, undocumented immigrants known as “Dreamers” who were brought illegally to the United States as kids, a jubilant Romero began applying for a two-year renewable permit to work and stay in the United States temporarily, thanks to an administrative directive issued by President Obama in June. Romero says she celebrated because finally she could drive and work legally.

Then that same day, Arizona Gov. Jan Brewer, who had become a conservative superstar after wagging her finger at the president on an airport tarmac and subsequently calling Obama’s Dreamer directive “back-door amnesty,” fired back at Obama by issuing her own directive.

Governor Jan set off a heated national legal debate and scored points with her conservative fans by issuing an “executive order” denying Arizona’s 80,000 Dreamers drivers’ licenses and state identification cards, along with a handful of state benefits. That evening, Brewer said her order clarified that there would be no state-funded benefits and “no driver licenses for illegal people.”

Federal law will prevent most Dreamers from accessing Medicaid or food stamps, and Arizona law bans them from enjoying a few state benefits, such as state-subsidized child care, unemployment, and state contracts. Much of Brewer’s administrative order was redundant, but seemed to set off yet another skirmish in the state’s epic battle between old white people and young brown people.

But Brewer’s driver-license prohibition could spell misery for Arizona Dreamers. In Phoenix, a sprawling city surrounded by a web of suburbs with limited public transportation, many have no choice but to drive to work.

While Democrats blasted Brewer for mean-spirited anti-Obama gasbagging with her executive order, the ACLU of Arizona and national immigration lawyers and activists scrambled to read Arizona’s motor vehicle laws Thursday.

Their conclusion: Brewer doesn’t understand the linkage between federal immigration law and Arizona’s drivers’ license statute. And that could open the Grand Canyon State to a slew of lawsuits.

Brewer, who once accused Obama of giving Dreamers amnesty, now seems to be signaling that Dreamers do not have amnesty. She argues that Dreamers may be getting a temporary reprieve from deportation under the Obama directive, but nevertheless will not be legally present in the United States—and thus can’t legally drive in Arizona.

Immigration lawyers counter that the president’s directive will indeed make Dreamers legally present in the country—which entitles them to Arizona drivers’ licenses.

The legal debate over the drivers’ licenses centers on the arcane immigration-law concept of being lawfully present vs. having lawful status.

Arizona law requires drivers’ licenses be issued to those lawfully present under federal immigration law. Thanks to the Obama directive, Dreamers soon will be lawfully present. The state’s driver-license law doesn’t require lawful status, which Dreamers will not get under the Obama directive.

But Brewer “uses presence and status interchangeably,” says Alessandra Soler, executive director of the ACLU of Arizona.

“Whoever reviewed this governor’s executive order didn’t understand immigration law,” Soler told The Daily Beast. “The governor’s order is based on bad advice … This is similar to problems we’ve seen with SB 1070 [Arizona’s immigration law, signed by Brewer]—another example of her getting involved in federal immigration matters she has no business doing.”

And Danny Ortega, a prominent Phoenix lawyer and former chair of the National Council of La Raza, said that for now he’s reserving an opinion on which side will win, but described Brewer’s move as pure political posturing.

Brewer’s spokesman, Matthew Benson, said the governor is neither posturing politically nor receiving bad legal advice. The governor’s take is that even with Obama’s directive, Dreamers won’t be legally present in Arizona—and thus state law prohibits them from driving, he said in an interview.

Dreamers “have neither legal status nor legal presence ... The governor is merely upholding Arizona law, as is her duty,” he added in an email.

Others disagree.

“As a matter of federal immigration law, the governor’s office is simply wrong,” said Ben Winograd, staff attorney for the American Immigration Council in Washington. Dreamers, he says, “are considered to be lawfully present despite lacking valid immigration status.”

The upshot: despite the governor’s executive order, Dreamers probably will be able to drive to work legally, although they might have to take Brewer to court.

If nothing else, the governor’s executive order dampened the spirits of many Arizona Dreamers. Zulleth Romero and several other undocumented youths spent the night on the lawn of the Arizona Capitol, protesting Brewer’s order. Thursday morning, Romero and other Dreamers visited Brewer’s office in hopes of meeting with her. But Romero said “we were told she wasn’t available.”