The battle over President Obama's top counterterrorism aide escalated Thursday when Sen. John McCain blasted John Brennan for accusing Republicans of aiding Al Qaeda by being critical of his response to the failed Christmas Day airline attack.
The White House came to the defense of Brennan in the face of new criticism over a recent editorial in which he accused Republicans of aiding Al Qaeda for their criticism of the interrogation of failed Christmas bomber Umar Farouk Abdulmutallab.
White House spokesman Robert Gibbs said Brennan has 25 years experience in counterterrorism and doesn't wear his politics on his sleeves.
"John is there each and every day working in his office to try to do everything he can to keep the American people safe," Gibbs said, adding that the administration has asked him to stay on.
"And I would suggest, whether it's to Sen. (Kit) Bond or others on Capitol Hill, that these are decisions best left to people that have an understanding of counterterrorism, experience in counterterrorism and law enforcement, rather than to politicians on Capitol Hill," he said.
Republicans have assailed Brennan and the Obama administration for its handling of Abdulmutallab, who was read his Miranda rights after 50 minutes of questioning. Critics say Abdulmutallab should have been treated as an enemy combatant and subjected to a military tribunal instead of a civilian trial.
Bond of Missouri, the top Republican on the Senate Intelligence Committee, called for Brennan to resign after a hearing on Capitol Hill last week in which Brennan said he was tired of hearing criticism from armchair quarterbacks. His counterpart in the House, Rep. Pete Hoesktra, urged the administration to fire him.
On Tuesday, Brennan accused Republicans critical of his response to the failed Christmas Day airline attack of aiding Al Qaeda. Brennan made his accusation in an opinion article published in USA Today after several rounds of debate over who's politicizing the handling of Abdulmutallab.
"Politics should never get in the way of national security," Brennan wrote. "But too many in Washington are now misrepresenting the facts to score political points, instead of coming together to keep us safe.
"Politically motivated criticism and unfounded fear-mongering only serve the goals of Al Qaeda. .Terrorists are not 100-feet tall. Nor do they deserve the abject fear they seek to instill," he wrote
On Thursday, Sen John McCain, R-Ariz, said Brennan, President Bush's National Counterterorism Center director who was rejected by liberal allies of the Obama White House to be CIA director, "has lost all credibility ... with Republicans."
"No one that worked for the president questioned the patriotism or even the dedication to fighting the War on Terror as Mr. Brennan has about us, basically saying that we're assisting Al Qaeda," he said. "That's an insult. That is really far beyond any boundary that I ever saw in the Bush administration."
Asked whether Brennan should be dismissed or step down, McCain said, "All I know is he has lost any credibility he could possibly have with Republicans because of his comment impugning out integrity."
Fox News' Trish Turner contributed to this report.