Americans often suspect that their political leaders are arrogant and out of touch. But even then it is nearly impossible to fathom what self-delusion could have convinced Senator Pete Domenici of New Mexico that he had a right to call a federal prosecutor at home and question him about a politically sensitive investigation.

That disturbing tale is one of several revealed this week in Congressional hearings called to look into the firing of eight United States attorneys. The hearings left little doubt that the Bush administration had all eight  an unprecedented number  ousted for political reasons. But it points to even wider abuse; prosecutors suggest that three Republican members of Congress may have tried to pressure the attorneys into doing their political bidding.

It already seemed clear that the Bush administration’s purge had trampled on prosecutorial independence. Now Congress and the Justice Department need to investigate possible ethics violations, and perhaps illegality. Two of the fired prosecutors testified that they had been dismissed after resisting what they suspected were importunings to use their offices to help Republicans win elections. A third described what may have been a threat of retaliation if he talked publicly about his firing.

David Iglesias, who was removed as the United States attorney in Albuquerque, said that he was first contacted before last fall’s election by Representative Heather Wilson, Republican of New Mexico. Ms. Wilson, who was in a tough re-election fight, asked about sealed indictments  criminal charges that are not public.