aid. In a day of rapid-fire developments, Attorney General John Ashcroft excused himself from all matters involving Enron because of campaign contributions he received from it. In addition, Enron's auditors said they had destroyed numerous company documents and electronic communications. Page C1. The Justice Department said on Wednesday that it had created a nationwide task force to conduct a criminal investigation into the collapse of Enron, an energy trading company with close ties to Mr. Bush and many top administration officials. Today, the entire United States Attorney's office in Houston recused itself from the investigation, saying many of its approximately 100 lawyers, including the chief prosecutor, Michael T. Shelby, had family or other relationships with people affected by Enron's filing on Dec. 2 for reorganization under Chapter 11 of the bankruptcy law. The White House moved quickly to contain the damage. The White House spokesman said Mr. Bush was made aware of the phone calls to the