Procedural default doctrine is a legal principle which says that federal courts cannot review the merits of a habeas corpus petition if a state court has refused to review the complaint because the petitioner failed to follow reasonable state-court procedures. The purpose of this doctrine is to ensure that state prisoners not only become ineligible for state relief before raising their claims in federal court, but also that they give state courts a sufficient opportunity to decide those claims before doing so.
The procedural default doctrine precludes federal review of a state court's habeas decision when the state court's decision was based on adequate and independent state law, or when the federal issue was not fairly presented to the state courts and those courts would now hold the claim procedurally barred. The doctrine requires that petitioners fairly present their claims "in concrete, practical terms, so thatthe state court is sufficiently alerted to the federal constitutional nature of the issue." [Ward v. Jenkins, 2010 U.S. App. LEXIS 15150 (7th Cir. Wis. July 23, 2010)]