Controversy swirled over Mr Stephen Bannon's appointment as the next chief White House strategist, as many associate his name with bigotry, anti-semitism and even sexual assault.
One veteran Republican strategist John Weaver tweeted: "The racist, fascist extreme right is represented footsteps from the Oval Office. Be very vigilant America."
Before he became the Trump campaign's chief executive, the 62- year-old was chairman of right- wing website Breitbart News, which has become a platform for the Alternative Right - a movement that opposes establishment conservatives and is concerned with issues of white identity.
The former Goldman Sachs banker is seen as a firebrand who encouraged Mr Trump's brand of populism, which arguably led him to his historic victory over Democratic nominee Hillary Clinton.
"Like (seventh US President Andrew) Jackson's populism, we're going to build an entirely new political movement," he said in an interview with The Hollywood Reporter. "It's everything related to jobs. The conservatives are going to go crazy."
He also compared himself to the villain from Star Wars, saying: "Darkness is good... Dick Cheney. Darth Vader. Satan. That's power."
When it comes to Mr Bannon's personal life, reports have said he was charged with domestic violence, battery and dissuading a witness following an incident in 1996, but the case was ultimately dismissed when the victim - his ex-wife - did not show up in court.
Mr Bannon is also known to have made anti-Semitic statements, including not wanting his twin daughters to attend a school with Jews.
While his responsibilities have yet to be defined, he is likely to take charge of the Trump adminis- tration's vision and narrative. His name got top billing in the statement the transition team released on the first two White House appointments - a nod to Mr Trump's promise to "drain the swamp" and rid Washington of corrupt insiders.
Confident of his standing in the Trump administration, he likens himself to the right-hand man of King Henry VIII of England. "I am Thomas Cromwell in the court of the Tudors," he told The Hollywood Reporter. Melissa Sim