An effort to redefine what it means to be born in America.

NOGALES, Arizona - Of the 50 or so women bused to this border town on a recent morning to be deported back to Mexico, Inez Vasquez stood out. Eight months pregnant, she had tried to trudge north in her fragile state, even carrying scissors with her in case she gave birth in the desert and had to cut the umbilical cord.

“All I want is a better life,” she said after the Border Patrol found her hiding in bushes on the Arizona side of the border with her husband, her young son and her very pronounced abdomen.

The next big immigration battle centers on illegal immigrants’ offspring, who are granted automatic citizenship like all other babies born in America. Arguing for an end to the policy, which is rooted in the 14th Amendment of the United States Constitution, immigration hard-liners describe a wave of migrants stepping across the border to have what are dismissively called “anchor babies.”

The reality is more complex, with hospitals reporting some immigrants arriving to give birth in the United States but many of them with visas, crossing the border legally to take advantage of better medical care. Women like Ms. Vasquez, who was preparing for a desert delivery, are rare.

Still, Arizona - whose tough law granting the police the power to detain illegal immigrants is tied up in the courts - may again take the lead in an effort to redefine what it means to be an American. This time, Arizona lawmakers, joining legislators from other states, have decided against the painstaking process of amending the Constitution. The lawmakers are considering a move to create two kinds of birth certificates in their states, one for the children of citizens and another for the children of illegal immigrants.

The theory is that this could spark a flurry of lawsuits that might resolve the legal conflict in their favor.

“This is not a far-out, extremist position,” said John Kavanagh, one of the Arizona legislators leading an effort that has been called just that. “Only a handful of countries in the world grant citizenship based on the GPS location of the birth.”

Most Constitution scholars consider the birth certificates effort patently unconstitutional. “This is political theater, not a serious effort to create a legal test,” said Gabriel J. Chin, a law professor at the University of Arizona .

Kris Kobach, the secretary of state in Kansas and a law professor at the University of Missouri-Kansas City , argued that the approach the states were planning would hold up to scrutiny.

The legal theories are lost on Laura Gomez, 24, who crossed into Arizona from Mexico five years ago while expecting and is now pregnant with her second child. But like many other pregnant women in Arizona who are without papers, she has been following the issue with anxiety.

“It doesn’t seem fair to just change the rules like that,” Ms. Gomez said.

Despite being called “anchor babies,” the children of illegal immigrants born in the United States cannot prevent deportation of their parents. It is not until they reach the age of 21 that the children are able to file paperwork to sponsor their parents for legal immigration status.

A study released in August by the Pew Hispanic Center found that about 340,000 children were born to illegal immigrants in the United States in 2008 and became instant citizens.

In April, Representative Duncan Hunter, a California Republican who is one of those pushing for Congressional action on the issue, stirred controversy when he suggested that children born in the United States to illegal immigrants should be deported with their parents until the birthright citizenship policy was changed.

Immigrant advocates say intolerance is driving the measure. “They call themselves patriots, but they pick and choose which parts of the Constitution they support,” said Lydia Guzman, a Latino activist in Phoenix. “They’re fear-mongerers. They’re clowns.”

Scholars who have studied migration say it is the desire for betterpaying jobs, not a passport for their children, that is the main motivator for people to leave their homes for the United States.

Even Ms. Vasquez agrees with that. While she preferred to have her child be born in the United States, it was the prospect of a better economic future, with or without papers, that had prompted her and her family to cross when they did. “I’ll try again - but once the baby’s born,” she said.


By MARC LACEY