The Schuler Education Foundation said it will invest up to $500 million at top-tier liberal arts colleges to help them enroll more low-income and unauthorized immigrant students. The roughly 20-year-old foundation has already pledged tens of millions of dollars to five selective institutions: Bates, Carleton, Kenyon and Union colleges and Tufts University. Participating colleges will need to match the foundation's funding over five years. Colleges that work with the foundation need to meet all of their students' demonstrated financial need and be committed to raising the matching funds.