From U.S. News:
Soon after Gonzales became attorney general, his then chief of staff, Kyle Sampson, told Comey that Gonzales’s “vision” was to merge the deputy’s office with Gonzales’s own office. That meant that Comey would have lost some of his autonomy, becoming less of a leader and more of a senior staff member. A source close to Sampson says he merely wanted Gonzales and Comey to operate as a “seamless leadership team,” with “harmony rather than conflict,” and never meant to “degrade the status or authority” of the deputy. Comey didn’t buy it. “You may want to try that with the next deputy attorney general,” Comey is said to have responded to Sampson. “But it’s not going to work with me.”
No wonder Comey didn’t last long under Gonzales.