which assumes the rule of law by government, the Americans follow the British tradition of "sovereign immunity".  As a general rule the government, per se, cannot be sued for money damage without its consent, and individuals can be sued only for, under color of law, intentionally depriving someone of a clearly defined constitutional right.  Moreover, some officials like judges and policy makers, have an even greater level of legal protection.  Even when, e.g. Rumsfield, is sued in an official capacity in the United States, this is just another way of suing the government, he isn't personally responsible for any damages awarded.

In practice, the only remedy against an incumbent President for abhorent policy decisions is impeachment.

President Clinton's legal troubles set the precedent that governmental immunity is limited to the official acts of the President, and not to suits arising out of the private life of the President unrelated to his official duties.