According to a 1982 Supreme Court decision, all children, regardless of immigration status, have the right to attend public school in America. That's why the State Education Department sent out a memo reminding public schools to adhere to a bit of a "Don't Ask, Don't Tell" policy when it comes to student immigration status. The memo [PDF] states, "school districts may not deny resident students a free public education on the basis of their immigration status..., at the time of registration, schools should avoid asking questions related to immigration status or that may reveal a child’s immigration status, such as asking for a Social Security number."
The memo was released due to mounting pressure from the New York Civil Liberties Union, which found that students in 139 districts were requiring children's immigration papers for enrollment. However, no students were turned away because of their immigration status. SED spokesman Jonathan Burman told the Times, “Shortly after the story ran, we revisited the issue and felt that it would be helpful to districts to give them more comprehensive guidance," speaking of a New York Times story on the issue that ran in July.
The NYCLU was happy with the memo, though they wish the State had done more, earlier. Advocacy director Udi Ofer said, "There’s no question that a strong mandate would’ve been better. But the language included in this guidance makes it clear that school districts must amend their policies to be in compliance with constitutional law."