A security clearance is like an office stapler; it's something your employer provides that you need to do your job.

For certain jobs, people have to access highly sensitive information, like data generated by spy satellites or agents the U.S. has in place in foreign countries, and a security clearance is the government saying that after investigating these people, we, the government, believe they are trustworthy.

In keeping with Reagan's adage of "trust but verify," people with clearances still have to sign non-disclosure agreements (NDAs) in which they agree that the government can have their firstborn male child – yes, Virginia, the government is sexist – and any of their organs that the notorious RBG might need to live until the next Democratic president is elected.  Basically, it's a lot easier to sue someone for breach of an NDA than it is to convict him of espionage.

Each individual's security clearance is custom-tailored to what he needs to know for his job.

The "need to know" principle says that even if you have a clearance at the über-super-nearly James Bond cool level, you can see only the information relevant to what you're doing at work.

For example, if you're an analyst looking into the Iranian nuclear weapon program, you have a need to know if a key spy in Russia says Russia is providing specialized materials to the Iranian program, but you don't have a need to know if that same Russian says Russia is developing a sneaky new anti-satellite weapon.

How does this all relate to the Brennan case?  Many left-wing fanatics are saying that it's unconstitutional, dictatorial, etc. for Trump to have removed Brennan's clearance.

That's on par with saying it's unconstitutional, dictatorial, etc. for a company to say that when an employee leaves, or is fired, he can't take the office stapler with him.

Since Brennan is no longer working for the government, he no longer needs a clearance.  In fact, a clearance is useless for him.

Even if he had a clearance, he certainly couldn't be told any new classified information, since he no longer has a need to know.

Further, a security clearance is a privilege, not a right.  Good, honest people have been denied clearances for any number of reasons.  Someone who has relatives who could be coerced by our enemies because the relatives live in China or Russia may be denied a clearance because the government rightly knows that if given a choice between having their parents tortured to death in the old country or betraying America, some people would betray America.

There are innumerable "reporters" who would be glad to demand a clearance if anyone really believed that a clearance is a right that can't be denied to people.  Yet none of them has ever tried that approach, which is a fairly good indication that even the wackadoodles who pass as reporters in the fake news media don't believe that they have a constitutional right to a clearance or that it's dictatorial to deny them one.

People can lose their clearances, too.  Sometimes it's just because they no longer need them, and sometimes it's because the government has lost faith in them.

If someone discloses classified information carelessly or intentionally, and he's not Hillary, he will generally quickly lose his clearance. 

Any sign of significant untreatable mental illness can also lead to losing one's clearance.

While it's debatable if Brennan is clinically insane, what isn't is that he's been hinting about classified information, which is, in effect, revealing it – if someone says he has details about the latest Russian ICBM, he's disclosing the classified fact that the U.S. has that information even if he doesn't expose the actual numbers.  By continually implying that he has deep classified knowledge about Trump colluding with Russia, Brennan is telling us one of two things: either he's illegally revealing the classified fact that the U.S. Intelligence Community has proof that Trump colluded or he's lying through his teeth.

If it's the former, then Brennan should lose his clearance for intentionally disclosing classified information.  If it's the latter, he should lose his clearance because he's no longer trustworthy.

The bottom line is that Brennan has been acting as though he's still in a position of power by using his "secret" knowledge to try to nullify the 2016 election.  He has no right to a clearance, and there is no reason why Trump should allow Brennan to keep getting classified information from his old cronies in order to attack the democratic process in America.

You can read more of Tom's rants at his blog, Conversations about the obvious, and feel free to follow him on Twitter.