In their "What if Roe Fell 2007?" report they think Delaware and Rhode Island are states at "high risk" to outlaw abortion if Roe is overturned. Illinois is listed as a state at "moderate risk."
They come to their conclusions seemingly based almost completely on whether old laws have be explicitly overturned in the legislature or not and pay almost no attention to the current makeup of the state legislature. If a state has an abortion ban which has been ruled unconstitutional by the courts (like Rhode Island) the state is at "high risk" to outlaw abortion because "state officials may seek to set aside the court rulings in order to enforce the ban if Roe is overturned." There doesn't seem to be any thought to whether state officials would actually do this or how the state's supreme court would rule.
They also list Michigan's Legal Birth Definition Act as an "Abortion Ban Bill" as if it outlawed all abortions and not just abortions where the unborn child is partially-born.