Blame the Russia investigation, Trump said.
Obama's attorney general gave a rare interview to NBC News.
The 2016 presidential candidate discussed Trump, Putin and Pizzagate with a few hundred young women, many in bright pantsuits, who waited for hours to see Clinton speak.
Republican attitudes toward the law enforcement agency have grown more negative over the past year.
Trump has said the FBI disliked Comey, but the emails suggest otherwise.
The letter, 11 days before the election, has been widely cited as one of the potential reasons Clinton ultimately lost to Trump.
McCabe's departure comes as Trump and Republicans step up attacks on the top law enforcement agency.
In a heated phone call, Trump reportedly lashed out at the wife of Andrew McCabe, who stepped down as FBI deputy director Monday.
Bowdich was associate deputy director under Comey and was involved in the response to the San Bernardino shooting.
Trump and his allies had scrutinized McCabe for campaign contributions his wife once received.
Former FBI Director James Comey, whose controversial decisions—from the Clinton letter to the Trump memos—have been excoriated by both Democrats and Republicans, will begin teaching a college ethics course in the fall.
President questioned top FBI lawman on how he voted, raising concerns amongst former officials.
Robert Mueller reportedly wants to know more about Comey's Trump memos.
After Christopher Wray's threat, the attorney general apparently backed off from his call to fire Andrew McCabe.
The Department of Justice said on Friday that President Donald Trump did not invite his maligned attorney general to a legislative discussion group at Camp David this weekend.
Trump and other Republicans have accused Andrew McCabe of misconduct.
A former U.S. attorney now says the attorney general "must go" if a new report saying he tried to undermine the Trump-Russia investigation is true.