On August 25, 2016, three months before Trump's Inauguration, CIA Chief, John Brennan, briefed Harry Reid as to the contents of the Steele Dossier which wound up in a letter from Reid to the FBI, which, in turn, was used as a predicate for the first FISA Court warrant to spy on the Trump Campaign . . . . justification enough . . . .
reason for ending his security clearances.
More than this, Brennan continues to label Trump a "subversive," accusing him of treason, and, defending that position. The man needs security clearance like he needs another mouth.
Now you know.