Given what’s in those documents, it was astonishing to hear Mr. Gonzales continue to insist yesterday that he had no personal knowledge of discussions involving the individual attorneys. Senator Charles Schumer, Democrat of New York, was right on the mark when he said that if Mr. Gonzales didn’t know what Mr. Sampson was doing, “he doesn’t have the foggiest idea of what’s going on” at his department. Fortunately, last year’s election left Democrats like Mr. Schumer in the majority, with subpoena power. Otherwise, this and so many other scandals might never have come to light.

Mr. Gonzales, who has shown why he was such an awful choice for this job in the first place, should be called under oath to resolve the contradictions and inconsistencies in his story. Mr. Gonzales is willing to peddle almost any nonsense to the public (witness his astonishingly maladroit use of the Nixonian “mistakes were made” dodge yesterday). But lying to Congress under oath is another matter.

The Justice Department has been saying that it is committed to putting Senate-confirmed United States attorneys in every jurisdiction. But the newly released documents make it clear that the department was making an end run around the Senate  for baldly political reasons. Congress should broaden the investigation to determine whether any other prosecutors were forced out for not caving in to political pressure  or kept on because they did.

There was, for example, the decision by United States Attorney Chris Christie of New Jersey to open an investigation of Senator Bob Menendez just before his hotly contested re-election last November. Republicans, who would have held the Senate if Mr. Menendez had lost, used the news for attack ads. Then there was the career United States attorney in Guam who was removed by Mr. Bush in 2002 after he started investigating the superlobbyist Jack Abramoff. The prosecutor was replaced. The investigation was dropped.

In mid-December 2006, Mr. Gonzales’s aide, Mr. Sampson, wrote to a White House counterpart that using the Patriot Act to fire the Arkansas prosecutor and replace him with Mr. Rove’s man was risky  Congress could revoke the authority. But, he wrote, “if we don’t ever exercise it, then what’s the point of having it?”

If that sounds cynical, it is. It is also an accurate summary of the governing philosophy of this administration: What’s the point of having power if you don’t use it to get more power?