"It's a federal law suit. Why would the Bush Administration go after Fox?"
The federal government is a huge entity made up of many agencies that are still headed by partisans. One thing to remember about CLinton is that he committed one of the largest partisan purges in US history...which included the so-called DA Massacre that replaced all the US Attorneys. Unless Bush replaced these people, (which I don't recall him doing) these federal prosecutors, combined with Clinton-appointed federal judges, means Republicans aren't even safe from partisans in the DOJ.