There are two issues here. In order to have access to classified material at a given level you need both a clearance and a "need to know."
Different clearance levels require increasingly thorough background checks. These become increasingly costly in both time and dollars. Clearing a new person to TS/SCI can cost $100K and take up to two years. Individuals undergo periodic "bring up" reexaminations.
At its essence, a clearance is a measure of an individual's loyalty to the United States and their ability and willingness to safeguard the information to which they are entrusted.
The second element required for access to classified material is a "need to know." This is job related. Just because a person has a TS clearance that doesn't mean that they are allowed to see anything TS. This is particularly true when dealing with Sensitive Compartmented Information (SCI). I have been read on and off more compartments than I can remember. There are countless compartments that I never even knew the names of. This is by design.
Given the high cost in time and money, it is in the government's best interest NOT to terminate a clearance when a person leaves a job (unless they were fired for cause). Their "need to know" goes away immediately and no one should discuss classified material with them regardless of the reason.
People change jobs for many reasons from retirement to promotion to a contract ending. This is why clearances are generally kept active for for two years or until they go out of scope (bring up exam needed).
Hope this helps. I will answer additional questions if I can.
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)
I agree with these comments. One of the final comments should be stressed and that is once an individual leaves a project or a job, their access to the classified information is removed. The clearance goes into a dormant state until a new sponsor applies on the individual’s behalf for new access - ie a change of job may take a couple of weeks to transfer from one sponsor to another. In the case of these gov officials, once they leave office, their access should be removed and they never again receive any program-related information. They maintain their clearance, but it is shelved in the event they assume a new position with the same access requirement. BUT LIKE ANY OTHER CIVILIAN, ONCE THEIR SHELVED ACCESS EXPIRES, THEY SHOULD LOSE NOT ONLY ACCESS, BUT THE CLEARANCE ITSELF. HRC has been out of office since February 2013, at most she should have retained a clearance for five years aftwards, but she should have had access to NO CLASSIFIED INFORMATION SINCE 2013.
Seems to me that a security clearance is a legal means for the government to stifle free speech, which is accepted voluntarily.