Black children face an uphill climb from the minute they enter school.

Even preschoolers are getting suspended from U.S. public schools — and they're disproportionately Black, a trend that continues up through the later grades.

Data to be released Friday by the Education Department's civil rights arm finds that Black children represent about 18 percent of children enrolled in preschool programs in schools, but almost half of the students suspended more than once. Six percent of the nation's districts with preschools reported suspending at least one preschool child.

Advocates have long said that get-tough suspension and arrest policies in schools have contributed to a "school-to-prison" pipeline that snags minority students, but much of the emphasis has been on middle school and high school policies. This data shows the disparities starting in the youngest of children.