The Supreme Court today struck down most of the outrageous Arizona immigration law, but upheld the one portion that received most of the negative attention when the law was first passed: the infamous "papers, please" section requiring the police to demand proof of citizenship from anyone they stop who "looks" like they could be an undocumented immigrant. Most of the coverage of the decision today will focus, rightly, on how this law will affect people who actually are in the country illegally, but it's also important to remember this law allows the police to arrest someone who is a legal resident but has the misfortune to be a person of color out and about who left her driver's license at home ... or doesn't even have one. Which is why I suspect that while this law will negatively affect a whole swath of people, young people and women will be disproportionately affected.
Young people who are legal residents are in serious danger because of this law, because the cops are much more likely to harass young people for doing normal things like loitering, but young people often, by virtue of their age, don't have legal identification. Even if they're old enough to get drivers licenses, increasing numbers of teenagers and young adults are opting out of getting drivers licenses. While there are state-issued IDs that you can get instead when you turn 18, a lot of people understandably don't bother until they're 21 or so, leaving them uniquely vulnerable to being picked up for not having identification proving they're legal residents.
Additionally, women, especially in poor or rural communities, are also much more likely to be out and about without legal identification than men, especially if they don't drive or drive often. Women that are poor or undereducated are much more likely to be stay-at-home mothers with few resources, which makes it very easy to let concerns about up-to-date licenses or ID slip, especially if you don't drive a car much because someone else in the household is using it for work. If your daily life is dedicated to running errands for your family, you may not have much cause to worry about keeping all your papers in order generally, until it's too late and you're finding yourself in jail for not being able to prove citizenship on the spot. Supporters of this law claim that they're only interested in deporting more people who are here illegally, which is itself a troubling notion, but the potential for collateral damage in this war on undocumented immigrants is high.