John Brennan is shown speaking here at the Richard Nixon Presidential Library in Yorba Linda, Calif., in 2016, when he was serving as CIA director. Brennan says he’s considering a legal challenge to President Trump’s decision to revoke his security clearance.

John Brennan is shown speaking here at the Richard Nixon Presidential Library in Yorba Linda, Calif., in 2016, when he was serving as CIA director. Brennan says he’s considering a legal challenge to President Trump’s decision to revoke his security clearance.