One in three school districts in Westchester improperly requires immigration or other documents before enrolling a student, 28 years after the U.S. Supreme Court ruled that all children have a right to a public education regardless of whether they are in the country legally. The New York Civil Liberties Union charged Friday that 14 Westchester districts are among 139 across the state that ask for visas or other documents when a child registers. One district in Rockland County, Nyack, is also on the list. No Putnam County district is included. "Though some of these school districts undoubtedly seek to exclude immigrant children, many of the offending districts are surely unaware that their registration requirements are discriminatory," said the NYCLU's executive director, Donna Lieberman.