In Clinton v. Jones, the Court declined to extend the immunity recognized in Fitzgerald to civil suits challenging the legality of a President's unofficial conduct. In that case, the plaintiff sought to recover compensatory and punitive damages for alleged misconduct by President Clinton occurring before he took federal office. The district court denied the President's motion to dismiss based on a constitutional claim of temporary immunity and held that discovery should go forward, but granted a stay of the trial until after the President left office. The court of appeals vacated the order staying the trial, while affirming the denial of the immunity-based motion to dismiss. The Supreme Court affirmed, permitting the civil proceedings to go forward against the President while he still held office.

    In considering the President's claim of a temporary immunity from suit, the Court first distinguished Nixon v. Fitzgerald, maintaining that "[t]he principal rationale for affording certain public servants immunity from suits for money damages arising out of their official acts is inapplicable to unofficial conduct." Clinton v. Jones, 520 U.S. at 692-93. The point of immunity for official conduct, the Court explained, is to "enabl[e] such officials to perform their designated functions effectively without fear that a particular decision may give rise to personal liability." Id. at 693. But "[t]his reasoning provides no support for an immunity for unofficial conduct." Id. at 694.
http://www.usdoj.gov/olc/sitting_president.htm


it is fair to say that there exists an important national interest in ensuring that no person -- including the President -- is above the law. Clinton v. Jones underscored the legitimacy and importance of allowing civil proceedings against the President for unofficial misconduct to go forward without undue delay.