Big distinction between patriotism and partisanship - hopefully at least. No doubt Brennan would do nothing to help Trump, but I have to assume he - like you and me - would do anything he could to help our country regardless of whether it helps the administration, too. The trouble with your assumption about re-establishing clearance is when time is of the essence, and also implies that the temporary clearance would only be used in universally recognized dire circumstances - which, as we know, may not be recognized at all at the time. I may be naive, but I'd be very surprised if having security clearance is the same as receiving daily briefings and/or having unlimited access to classified info simply upon request or out of curiosity to what your successors and former coworkers are doing before lunch. I would hope that retaining clearance means not having to go through the vetting process - even expedited - in order to be able to converse and consult with others with the same clearance in need of one's expertise or experience in various matters that may or may not be recognized as, or turn out to be for that matter, important or dire prior to the consultation.