WASHINGTON (AP) — Justice Elena Kagan recalled the moment 30 years ago when her boss looked at her "as though I must have lost my mind."

The boss was Justice Thurgood Marshall and the setting was his Supreme Court office, where Kagan was spending a year as a law clerk after graduating from Harvard Law School.

Kagan had just delivered what she deemed a clear and simple explanation for why Marshall should side against a North Dakota girl who lived 16 miles from her school and whose family could not afford the bus service to get her there. The school district wouldn't waive the fee.

The legal gia...