Mueller is investigating Russia's alleged interference in the 2016 election and any collusion by Trump's campaign.
Some Democrats quickly demanded that Whitaker should recuse himself from supervising Mueller, as Sessions did because Whitaker wrote an opinion piece for CNN in August 2017 that argued Mueller had too much latitude in his investigation.
One associate, Jerome Corsi, said in a video recording Monday that he's "been involved in a really constant basis" for two months with Mueller's investigation.
In fact, Trump has repeatedly referred to Mueller's probe as a "witch hunt".
The special counsel's office declined to comment Wednesday after Sessions' resignation.
The Democrats said they also want the Justice Department to protect the integrity of Mueller's investigation and to preserve relevant documents.
CBS News has learned former New Jersey Gov. Chris Christie is being considered to replace Jeff Sessions as attorney general.
Rep. Jerry Nadler (D-N.Y.), who will oversee the committee now that the Democratic Party has taken control of the House, cautioned the president that he will now face far more oversight from lawmakers and warned that Sessions' firing and subsequent appointment of loyalist Matthew Whitaker to serve as acting attorney generalhas thrown the nation into a "constitutionally perilous moment". US Senate Minority Leader Chuck Schumer shortly after the news broke said in a statement that Whitaker in his new role should recuse himself from overseeing Mueller's investigation. Whitaker criticized both aspects a year ago, and as he is now taking over oversight of the probe, he could try to strangle it, or even rescind Mueller's appointment.
The president can not directly fire the special counsel.
Ruth Bader Ginsburg Hospitalized With Fractured Ribs After Fall
Prior to her appointment, Ms Ginsburg focused her work on women's rights and started the first law journal dedicated to the topic. President Donald Trump has appointed two justices to the court, Neil Gorsuch and Brett Kavanaugh , since taking office.
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Mowry-Housley's twin sister and former co-star, Tia Mowry , also sought information through social media posts early in the day. Long opened fire inside Borderline about 11:20 p.m., during the bar's "college country night" event, authorities said.
Dez Bryant will get his chance at revenge with the Saints
They're also replacing the mediocre Meredith, who isn't much faster than Bryant, with an accomplished receiver. During the preseason, Bryant had been inside the Browns facility but Cleveland elected not to sign him.
Trump's relentless attacks on Sessions came even though the Alabama Republican was the first USA senator to endorse Trump and despite the fact his crime-fighting agenda and priorities, particularly his hawkish immigration enforcement policies, largely mirrored the president's.
"If this wasn't about the Mueller probe, why install an Acting AG other than the DEPUTY Attorney General?" he wrote in a tweet.
Sessions recused himself from managing the investigation because of his own past involvement in the Trump campaign.
"Sessions allowed the Department of Justice to function as the political arm of the Trump administration to undo fundamental rights that protect each of us, disregarding years of legal precedent and settled law".
He found satisfaction in being able to reverse Obama-era policies that he and other conservatives say flouted the will of Congress, including by encouraging prosecutors to pursue the most serious charges they could and by promoting more aggressive enforcement of federal marijuana law.
Some Republicans appear to have shared the Democrats' concern over the future of the inquiry, which is being led by Special Counsel Robert Mueller. The Justice Department, responding to a Washington Post report, soon acknowledged that Sessions had actually had two encounters during the campaign with the then-Russian ambassador.
The American Civil Liberties Union (ACLU) Executive Director Anthony Romero said in a statement on Wednesday that the US Senate must ensure that whomever Trump nominates to replace Sessions will not interfere in Mueller's Russian Federation investigation.
Sessions, who likely suspected his ouster was imminent, was spotted by reporters giving some of his grandchildren a tour of the White House over the weekend.