From the report:
NPR now has new information about that plan. According to someone who's had conversations with White House officials, the plan to fire all 93 U.S. attorneys originated with political adviser Karl Rove. It was seen as a way to get political cover for firing the small number of U.S. attorneys the White House actually wanted to get rid of. Documents show the plan was eventually dismissed as impractical.
The Justice Department documents released today include a spreadsheet ranking all 93 prosecutors. The chart ranks them on whether they have Hill experience, campaign experience, and — in the last column — whether they're members of the Federalist Society, a conservative legal group.