The Bush administration has done a terrible job of explaining its decision to fire eight United States attorneys. Story after story has proved to be untrue: that the prosecutors who were fired were poor performers; that the White House was not involved in the purge. But the administration has been strangely successful in pushing its message that the scandal is at worst a political misdeed, not a criminal matter.

It is true, as the White House keeps saying, that United States attorneys serve “at the pleasure of the president,” which means he can dismiss them whenever he wants. But if the attorneys were fired to interfere with a valid prosecution, or to punish them for not misusing their offices, that may well have been illegal.

In law schools, it is common to give an exam called the “issue spotter,” in which students are given a set of facts and asked to identify all the legal issues and possible crimes. The facts about the purge are still emerging. But based on what is known — and with some help from Congressional staff members and Stephen Gillers, a law professor at New York University — it was not hard to spot that White House and Justice Department officials, and members of Congress, may have violated 18 U.S.C. §§ 1501-1520, the federal obstruction of justice statute.

Some crimes that a special prosecutor might one day look at:

1. Misrepresentations to Congress. The relevant provision, 18 U.S.C. § 1505, is very broad. It is illegal to lie to Congress, and also to “impede” it in getting information. Deputy Attorney General Paul McNulty indicated to Congress that the White House’s involvement in firing the United States attorneys was minimal, something that Justice Department e-mail messages suggest to be untrue.