Of course, something the Demoncrats discovered how to do with Clinton and now with Obama is to get their political friends permanent, senior-level civil-service jobs that don't get replaced when the administration changes. The jobs pay less than working in the private sector (at least for them), but committed leftists are willing to take less of a salary in order to advance the cause (this is a large part of why most teachers are liberal).
The reason Sessions has not cleaned it out is simple ? WAY TOO MANY YEARS IN THE SENATE better known as the do nothing branch of the government.....They act like a private world. Example they did not vote on Kerry by ballot they stood up as a group and did a voice vote including all of the crooks there now.....