Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: George W. Bush went home to Texas nearly six years ago, but the nation is still working through the contentious national security legacy he left behind. A hotly disputed Senate report on the CIA's brutal interrogation tactics is tearing open barely healed political wounds first opened after the September 11, 2001, attacks. The report found CIA tactics were more brutal than previously known and accused the agency of keeping the Bush White House and Congress in the dark about them. The questions raised by the Intelligence Committee's document -- about how to wage a relentless war on terrorism within constitutional and moral constraints -- seem as intense as ever.Bush anti-terror legacy still contested six years after he left officeObama warns against refighting old argumentsMcCain: the American people 'need answers'Obama's own 'war on terror' tactics in question 
 Question:His remarks were particularly notable because Obama defeated _ in 2008 in an election that served as a rejection of Bush's national security leadership.

McCain