(CNN)During the campaign, Donald Trump's inner circle was so small, it fit on his election night stage.
Who has Donald Trump's ear?
Now, a handful of those top advisers will follow the President-elect into the West Wing, influencing policy and helping to guide the first-time politician through his first months as President.
The rough and tumble team that led Trump's unprecedented campaign and now will shape his new administration include the top Republican Party leader, a controversial media mogul, Trump's son-in-law, and his third -- and final -- campaign manager.
Leading the group as Trump's new chief of staff is former RNC Chair Reince Priebus, who kept an arms' length distance from the billionaire during the Republican primary. Priebus then used a ground operation he spent years building up to help Trump win the presidency.
In the new administration, Priebus will be both doorkeeper to the Oval Office and a conductor keeping White House trains running. But his most difficult and important job will be trying to keep Trump himself on track. That's not a small task for a candidate who broke all the rules during his campaign and has spent his transition period communicating about international policy through Twitter.
His partner in that task is Steve Bannon, the former head of Breitbart News who Trump has named chief strategist and senior counselor. Bannon and Priebus will work side-by-side in the White House, but their political philosophies have been markedly different. Sources familiar with their relationship say Trump respects Bannon as an equal, and his role in the new administration will be to work with the President-elect on shaping the big picture.
Bannon outlined some of that vision in rare interview with Breitbart News Media after the election. "The hobbits or the deplorables had a great run in '16," Bannon said. "Everyone mocked then and ridiculed them and now they've spoken. I think '17 is going to be a very exciting year. I think the key is hold people accountable."
Then, there is Trump's son-in-law Jared Kushner, who will be the only family member to get an official administration title: White House senior advisor. The official role for Kushner is unusual, if not unprecedented, and will allow him to continue the integral role he played through Trump's campaign: organizing, advising, and now, sources say, playing conduit to Trump's cabinet. In interviews since the election, Trump has said he wants Jared working on foreign policy, specifically on a deal for peace in the Middle East.
In an interview with CNN prior to the election, Trump's former campaign manager, Kellyanne Conway, described a very close relationship with Trump's son-in-law who was integrally involved in running the campaign, especially on budgeting. "I'm very close to Jared. We talk many times a day," she said. "He's obviously a brilliant businessman."
Conway, who has in many ways become the face of team Trump, also still has a considerable amount of influence with the President-elect and will serve as counselor to the President in the new administration.
Another Trump insider, David Urban, who ran the billionaire's campaign in Pennsylvania and worked closely with Trump and his family, described Kushner as a "very thoughtful, bright individual who listens to lots of folks" and is "very collaborative in his decision making process." Urban said Trump's inner circle is made up of four "very important" people: Jared, Reince, Steve, and Kellyanne. "They all get to bend his ear," Urban said. "And when things get done, they're all at the table."
Remaining outside that official White House inner circle will be one of Trump's closest advisers, his daughter Ivanka. As her husband joins the administration in a formal capacity, Ivanka has said she will spend time settling their three children into life in Washington. While her official role is still to be determined, transition aides have already started reaching out to congressional staff on childcare proposals -- the policy issue she spearheaded during her father's campaign.
Trump's team may be unconventional, but the idea of a powerful inner circle has precedence in prior administrations. The small group of influential advisers surrounding Trump may be most similar to the so-called Big Three that Ronald Reagan began his presidency with: Ed Meese III, James Baker III, and Michael Deaver. They referred to themselves as "the triumvirate" because they worked so closely together. They were thought of as the most powerful group in Washington until infighting broke up the group.
Unlike the President-elect, George W. Bush took office with a large team of campaign advisers. But as with Trump, only a few really had sway: Karen Hughes, Vice President Dick Cheney, and famous Bush strategist Karl Rove.
Still, one transition source compared the Trump structure to that of President Barack Obama at the start of his first term when David Axelrod, Valerie Jarrett and Rahm Emanuel split responsibilities.
Regardless of who is advising a president, a key question is how he ultimately makes decisions. Urban said based on his time working closely with Trump during the campaign that the President-elect takes advice from "a wide range of individuals both on a formal and informal basis."
He described Trump as involved on a "granular level" in the Pennsylvania campaign -- even calling Urban personally to ask about details of their state strategy. When it comes to management style, Urban said Trump is "informal" and as someone who likes action.
"He is someone who wants answers, "Urban said. "He has an action-bias."
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According to other sources familiar with how Trump operates, his decision-making process varies with the subject matter. If it is an issue that Trump is comfortable with, he makes quick confident decisions. When it is an issue that he is unsure about, such as whether to select Mitt Romney for secretary of state, he can be swayed by the last person in the room. And on issues he knows little about, such as picks for top intelligence jobs, he turns to those who do know, like his incoming Vice President Mike Pence.
Trump, like most leaders, also relies on a kitchen cabinet of close friends and confidantes, including hedge fund manager Anthony Scaramucci, who will also take a White House job.
During the campaign, this small circle managed to successfully steer Trump to victory, but the task at hand changes at noon on Friday. It remains to be seen how this inner circle will run the White House and, more importantly, how Trump will perform as President.