Conversation so far:
What was John O. Brennan nominated for?
Obama nominated John O. Brennan as his next director of the CIA on January 7, 2013.
Was John O. Brennan a popular vote among others?
No, Kentucky Senator Rand Paul began a talking Senate filibuster prior to the vote to elect John Brennan as the next CIA Director.

Question: What were his qualifications that made him eligible to be nominated?
Self-contained rewrite: What were John Brennan's qualifications that made him eligible to be nominated?