John Brennan, Obama's initial pick for director of the Central Intelligence Agency, was forced to withdraw from consideration because of his past support for the Bush administration's "enhanced interrogation techniques".
Brennan previously served as head of Bush's "National Counterterrorism Center, an interagency headquarters for intelligence sharing and analysis created three years after the Sept. 11 attacks". Additionally, "he was deputy executive director of the CIA from 2001 to 2003, as the Bush administration's controversial interrogation and secret rendition program was created."
If you oppose what Bush did with counterterrorism and intelligence, you should oppose Brennan. Of course, during his campaign, Obama opposed what Bush did with counterterrorism and intelligence
Now, Obama has selected Brennan to be his top advisor on counterterrorism.