(CNN) At his first polygraph test to enter the CIA, the future director had a secret.
John Brennan on Thursday recalled being asked a standard question for a top security clearance at his early CIA lie detector test: Have you ever worked with or for a group that was dedicated to overthrowing the US?
"I froze," Brennan said during a panel discussion about diversity in the intelligence community at the Congressional Black Caucus Foundation's annual conference. "This was back in 1980, and I thought back to a previous election where I voted, and I voted for the Communist Party candidate,"
Brennan was responding to a question about barriers to recruiting diverse candidates for the intelligence fields, including whether past records of activism could hurt someone applying for a clearance later in life.
The CIA director said the agency's mission is to protect the values of the Constitution -- which include free speech.
"We've all had indiscretions in our past," he said, adding neither some drug experimentation nor activism was a non-starter. "I would not be up here if that was disqualifying."
He proceeded to tell the story of his test.
"I froze, because I was getting so close to coming into CIA and said, 'OK, here's the choice, John. You can deny that, and the machine is probably going to go, you know, wacko, or I can acknowledge it and see what happens,'" Brennan said.
He said he chose to be forthcoming.
"I said I was neither Democratic or Republican, but it was my way, as I was going to college, of signaling my unhappiness with the system, and the need for change. I said I'm not a member of the Communist Party, so the polygrapher looked at me and said, 'OK,' and when I was finished with the polygraph and I left and said, 'Well, I'm screwed.'"
But he soon got his admission notice to the CIA and was relieved, he said, saying that though the agency still had long strides to make in accepting gay recruits and minorities, even then it recognized the importance of freedom.
"So if back in 1980, John Brennan was allowed to say, 'I voted for the Communist Party with Gus Hall' ... and still got through, rest assured that your rights and your expressions and your freedom of speech as Americans is something that's not going to be disqualifying of you as you pursue a career in government."