Just months later, Patel was elevated to a new role at the Pentagon after Esper and other top defense officials were fired by Trump. Trump’s decision to install Patel as chief of staff for then-acting Defense Secretary Chris Miller was widely viewed as a reward for the loyalty he had demonstrated and would come to define his subsequent rise in the years that followed.

That appointment came after Trump sought to install Patel as deputy FBI director, a position that is traditionally held by a career FBI agent, a move that then-Attorney General William Barr blocked.

While at the Pentagon, Patel worked to help Trump try to overturn the 2020 election results in yet another demonstration of loyalty that has become a prerequisite for candidates seeking top jobs in his second administration.

Those relationships and Patel’s previous face time with Trump would prove valuable as the president-elect mulled over candidates to serve as FBI director during his second term.

Patel benefited from an informal and personality-based interview process for the job, two sources familiar with the discussions said. He was also buoyed by the backing of prominent voices in the decision-making process, including Donald Trump Jr., Eric Trump and Ric Grenell – endorsements that gave him an edge over other top candidates like former GOP Rep. Mike Rogers, the sources said.

Another source close to the transition also characterized Patel’s views related to the FBI as “radical,” even for those in Trump’s orbit who share the view that major changes are needed at the agency.

“This was Trump getting back at the FBI,” the source said.

Given the president-elect’s rhetoric around retribution during the campaign, there is an expectation that Patel may be primed to investigate Trump’s political adversaries. Asked during his interview on NBC’s “Meet the Press” about previously saying he would direct his Justice Department to appoint a special prosecutor to investigate President Joe Biden, Trump said he would not but left the door open for top DOJ officials to make their own determinations, including his pick for attorney general, Pam Bondi.

“No, I’m not doing that unless I find something that I think is reasonable,” Trump said in the interview, which aired Sunday. “But that’s not going to be my decision. That’s going to be Pam Bondi’s decision, and, to a different extent, Kash Patel, assuming they’re both there, and I think they’re both going to get approved.”

Trump suggested he had concerns that Patel’s vocal support of the MAGA movement might make him a difficult pick, but instead, Trump said, conservatives have rallied to support Patel.

“He’s very popular,” Trump said, calling Patel “very good and very fair.”

“I’ll tell you, I thought Kash may be difficult because he’s, you know, a strong conservative voice and I don’t know of anybody that’s not singing his praises,” Trump said.

One former colleague who has known Patel for over a decade believes criticism of him is blown out of proportion. He said Patel won’t use the FBI to pursue enemies and that his public comments are bluster intended to support Trump.

“He’s not gonna go after anyone, he’s going to go in there and focus the bureau on crime, going after the cartels and doing the work they should be doing,” the former colleague said.

It remains to be seen whether Patel will pass the confirmation vote in the Senate. But if he does, Patel will have positioned himself to act both as Trump’s shield – protecting him and his allies from the so-called deep state – and as Trump’s sword, using the country’s most powerful law enforcement agency to do his bidding.

By Evan Perez, Zachary Cohen and Holmes Lybrand, CNN