He also ran for Iowa Senate unsuccessfully.
The mobilization comes after President Donald Trump fired Attorney General Jeff Sessions Wednesday, replacing him with a man who has previously criticized the probe and offered suggestions on how to slow it down.
Lamar Alexander, Republican senator for Tennessee, also issued a warning from the Republican side, saying that the Senate will not confirm a successor to Sessions who would stop the Russian Federation investigation.
Mr Trump said: "According to NBC News, Voters Nationwide Disapprove of the so-called Mueller Investigation (46%) more than they Approve (41%)".
The Justice Department did not directly answer whether Whitaker would assume control of Mueller's investigation, with spokeswoman Sarah Isgur Flores saying he would be "in charge of all matters under the purview of the Department of Justice". However, it would be an immediate priority for Democratic investigations when they officially take control of the House in January. Republican Senator Susan Collins of ME criticized Trump for stripping Deputy Attorney General Rod Rosenstein of his role overseeing the probe. Whitaker had served as Sessions' chief of staff.
"Why is the President making this change and who has authority over Special Counsel Mueller's investigation?"
Christie met with Trump son-in-law Jared Kushner at the White House Thursday about prison reform, the White House told NJ Advance.
Whitaker, according to sources, is now overseeing everything at the Justice Department, including the Russian Federation investigation - despite calls from Democrats to recuse himself.
In addition to Sessions' ouster, Democrats are also interested in looking into Mr. Trump's tax returns, and global business dealings. But the former federal prosecutor went from being one of Trump's closest campaign advisers to an outcast.
"Trump putting himself above the law is a threat to our democracy, and we've got to get Congress to stop him", the group said on its website.
He also said there was no real evidence to support allegations Trump obstructed justice, and in an opinion article for The Hill newspaper he said Trump made the "right decision" by firing FBI Director James Comey in 2017.
After recusing himself from the Russian Federation probe, the staunchly conservative Sessions spent his time ramping up efforts to combat violent gangs, drug use and illegal immigration - all key components of Trump's law-and-order agenda.
Sessions clashed, though, with Jared Kushner, the president's son-in-law and senior adviser, resisting his proposals to overhaul the criminal justice system and standing by his hard-line approach to imprisonment and sentencing.