Courts are beginning to allow the so-called “show me your papers” clauses of tough new state immigration laws to take effect. But they’re warning states that the US Constitution frowns on any hint of profiling.

The US Supreme Court in June upheld “show me your papers” provisions in Arizona, which allow law-enforcement officials to ask for the immigration documents of people they suspect might be in the country illegally during routine stops. Now, lower courts are beginning to lift injunctions on similar laws in Georgia and Alabama, and a state judge was set to rule on whether to lift an injunction against it in Arizona itself, where Gov. Jan Brewer said that “the heart” of the state’s controversial law should “be allowed to take effect.”

As these laws take hold in the real world, focus is likely to shift to local and state police, who stand to face enormous pressure to use their expanded discretionary powers fairly and judiciously.

“The idea that this is the rubber hitting the road is exactly right,” says Stephen Vladeck, a law professor at American University’s Washington College of Law, in Washington. “Law enforcement already has lots of opportunities to stop most people on a daily basis for entirely minor offenses. The question is, stopping people for spitting on the sidewalk or driving with a broken taillight, are we going to see those increase in jurisdictions … that have the ‘papers, please’ provision? In other words, you cannot use the possibility that someone is undocumented to justify the stop in the first place.”

The issue has powerful emotional resonance in a country that historically valued freedom from government intrusion, raising the question of whether the “immigration laws really catch more people in the net than the Constitution should allow,” says Leon Friedman, a law professor at Hofstra University.

These concerns relate to the Constitution’s Fourth Amendment, which protects Americans from warrantless searches and seizures and restricts police from conducting random ID checks of people walking around on American streets. The immigration laws passed legal muster because a person has to have been detained or accused of a crime before police check their name against the e-Verify system, a federal immigration database.

“You can’t just stop them on the street and say, ‘Show your identification,’ ” Professor Friedman says. “There has to be a legitimate reason for stopping or arresting them, and then you can’t keep them indefinitely. In fact, the states have said, ‘We can keep you for a week,’ but the Supreme Court said they can’t do that.”

The bigger challenge for the implementation of “show me your papers” provisions may be the Constitution's equal protection clause, which guarantees that any jurisdiction gives its people "the equal protection of the laws."

“No American should ever live under a cloud of suspicion just because of what they look like,” President Obama said in June.

In both the Supreme Court decision in June and the 11th Circuit Court of Appeals decision Monday, justices essentially said they could not rule on the constitutionality because no one actually introduced any specific evidence that the laws invited racial or ethnic profiling – especially since the state laws in question expressly forbid such practices by police.

Arizona, for one, has circulated training videos to make sure that police stay within constitutional bounds when applying the new law.

Nevertheless, the general tenor of the courts is one of skepticism about the new breed of laws. For example, the 11th Circuit Court, which oversees Alabama, Georgia, and Florida, struck down significant parts of the Alabama and Georgia laws, including the creation of new crimes to punish those who aid, abet, even employ, illegal immigrants. Courts also nixed provisions that mandated immigrants carry their residency papers on them at all times.

Most significantly, the 11th Circuit struck down an Alabama provision that required school students to inform the state education department about their legal status, an exercise the state claimed was merely informational to be used to build better policy.

"We conclude that most of the challenged provisions cannot stand," the court said on Monday.

While one intent of the laws are clearly to cause illegal immigrants to leave, states have expressly said the main focus of tougher anti-immigration laws is to help federal agents enforce federal law – a powerful political argument in states like Arizona and Georgia, which have large populations of undocumented workers. Many people in those states also believe the federal government is impotent when it comes to controlling illegal immigration.

"The essence of Alabama's immigration law has been upheld by today's ruling," Republican Gov. Robert Bentley said in a statement. "The court is recognizing the state's authority to inquire on immigration status in certain circumstances."

But in Phoenix on Tuesday, District Court Judge Susan Bolton was set to consider a request from civil-rights groups to uphold the injunction on the new law, claiming they have new data suggesting it could lead to “needless suffering” for legal immigrants and even citizens.

“We have a good deal of evidence that the law would have a disparate impact on Latinos and Mexicans in particular, and that the law was enacted out of a discriminatory intent," Linton Joaquin, general counsel for the National Immigration Law Center, one of the groups leading the court challenge, told Reuters.