"I just retired a couple years ago, and I chose to get more active", O'Neill said.
And Schumer demanded to know whether there had been discussions with Whitaker concerning Mueller.
"I'm very anxious", said Nicole Lockett, waving an American flag.
Sessions had been an avid supporter from the beginning of the Trump campaign, but ran afoul of the President when he recused himself from the probe on Russia's interference after it was revealed that Sessions had had two meetings with the former ambassador from Russia, Sergey Kislyak.More news: Apple cancels iPhone XR production boost
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Since then, Whitaker, who had been Sessions' chief of staff, has faced pressure from Democrats to recuse himself from overseeing special counsel Robert Mueller, based on critical comments he made about the investigation before joining the Justice Department previous year. Campaign efforts include ending the Iraq war and combatting gun violence by ending politicians' affiliation with the NRA, but since 2016 the organization says it has been "a pillar of the Resistance to Trump".
Whitaker himself stayed out of the public debate Friday.
"At your request, I am submitting my resignation", Sessions said in the first line of a letter released by the Department of Justice.
But there has also been speculation Trump could try to kill or suppress the 18 month-old probe, pressing his view that Mueller leads a team staffed by Democrats operating under an illegal mandate.
As acting attorney general, Whitaker now has the power to wrest oversight away from Rosenstein, and take charge himself. I'm concerned Rod Rosenstein will no longer be overseeing the probe.
A federal appeals court that is weighing a legal challenge to Special Counsel Robert Mueller's authority said Friday it wanted to know whether the sudden ouster of Attorney General Jeff Sessions could impact or change the outcome of how it should rule.
"If Mueller wants to do any more subpoenas, if he wants to bring in Don Jr.to talk about the meeting at Trump Tower, he has to go through Whitaker to make that happen", said Scot Northern, who attended the protest in Iowa City.
In Kentucky, meanwhile, Senate Majority Leader McConnell said he expects Trump to nominate a new permanent attorney general "pretty quickly". However, Trump derided his argument, calling him "Mr Kellyanne Conway" and insisted that Conway, who has been a critic of Trump, was only interested in publicity.