Most states limit the defendant's ability to appeal when he pleads guilty. Yesterday, the California Supreme Court addressed one aspect of this limitation in People v. Johnson, S166894:

We granted review to resolve a conflict among appellate court decisions addressing the issue whether a defendant who desires to appeal from a criminal judgment on the ground that counsel rendered ineffective assistance regarding the defendant's request to withdraw a guilty or no contest plea first must obtain a certificate of probable cause. The Court of Appeal below, concluding that a certificate of probable cause was required, dismissed defendant's appeal. We affirm the judgment rendered by that court.