He didn't become Director of the Central Intelligence Agency under Obama until 2013, so it's not fair to label Brennan as a political ideologue since he served under both Republican and Democratic administrations.
Sanders also said President Trump plans to review intelligence access for other former officials.
Meanwhile, Benjamin Wittes of Lawfare said Comey told him he doesn't even have a security clearance to revoke and that he was "read out" when he left the government, which he said is normal practice.
The White House announced last month that it was reviewing the clearances.
"The President has a a constitutional responsibility to protect classified information and who has access to it and that's what he's doing is fulfilling this responsibility", Sanders said.
Mr. Trump added Mr. Brennan has a "history" that calls into question his "objectivity and credibility".
He may have lost his right to view classified material but he's gained something far more lucrative: Petty martyrdom at Trump's hands. He probably wanted to pull it weeks ago and was talked out of it by Kelly or Don McGahn or whoever, which would explain the July 26 date, only to say "to hell with it" after Brennan popped off about him again on Twitter yesterday.
Strzok's lawyer, Aitan Goelman, said in a statement Wednesday that security clearances shouldn't be taken away as a means of "punishing people who have criticized the President, or coercing others into silence".
Brennan in particular has been a frequent presence on TV slamming Trump.More news: Pregnant Reality Star Lyric McHenry, 26, Dies of Suspected Drug Overdose
Trump said he may also revoke the clearances of other critics, including former USA national intelligence director James Clapper, former FBI Director James Comey, former Obama national security adviser Susan Rice, former National Security Agency director Michael Hayden and former deputy Attorney General Sally Yates, among others. "I don't know what it is that is behind that, but I think that's why it's critically important that Bob Mueller and his investigators be allowed to continue their work unimpeded by Mr. Trump or anyone else in the administration".
Trump also said he was considering revoking the security clearances of other law-enforcement and intelligence officials, many of whom have been critical of him. Mr Brennan headed the CIA, the foreign intelligence service, when the alleged hacking took place and stepped down after Mr Trump won the election. "The president of the United States for the first time has made a decision to revoke a security clearance on the basis of a critic exercising his first amendment rights to free speech".
Director of National Intelligence Dan Coats was not consulted on revoking Brennan's clearance, an official with knowledge told CNN's Jim Sciutto.
McCabe is a former FBI deputy director who led the investigation into Clinton's email practices.
White House spokesperson Sarah Huckabee Sanders announced the decision at a White House briefing Wednesday, following through on the president's recent threat.
James Clapper, former U.S. director of national intelligence.
Lisa Page, an Federal Bureau of Investigation lawyer.
Former Vice President Joe Biden called Trump's act "unbecoming of a President", and warned that it would only embolden Brennan in his public crusade against Trump.