Greg Jacob, former counsel to Vice President Mike Pence, is seen testifying to the House Jan. 6 Committee. He is wearing a...

Who is Greg Jacob and why is he testifying in the Jan. 6 hearings?

The bulk of the Jan. 6 House Committee’s June 16 hearing focused on former Pence lawyer Greg Jacob’s testimony, which outlined the steps taken in the days leading up to the insurrection to keep the president in power.

READ MORE: Who are the witnesses testifying at the Jan. 6 hearings?

As a top advisor to the vice president, Jacob was part of the effort to rebut legal arguments cited by Trump that Pence could change the way Electoral College votes were counted, thereby changing the outcome of the 2020 election.

In the days leading up to the Capitol insurrection, Jacob disputed a memo from John Eastman, a lawyer affiliated with the conservative Claremont Institute, who argued Pence could refuse to accept the electoral votes from certain states and described the vice president as the “ultimate arbiter” of how the electoral votes would be counted.

Jacob testified that Pence first asked him about the legality of rejecting electors in early December of 2020. According to Jacob, Pence could not believe it would be legal, so Jacob drafted a memo explaining it was not.

“If the vice president implemented Professor Eastman’s proposal, he would likely lose in court,” Jacob wrote in the memo. “In a best-case scenario in which the courts refused to get involved, the vice president would likely find himself in an isolated standoff against both houses of Congress, as well as most or all of the applicable State legislatures, with no neutral arbiter available to break the impasse.”

At the June 16 committee hearing, Jacob testified that Pence was skeptical from the start.

“The vice president’s first instinct when he heard this theory was that there was no way our framers who abhorred concentrated power, who had broken away from the tyranny of George III, would have ever put one person, particularly not a person who had a direct interest in the outcome because they were on the ticket for the election, in a role to have decisive impact on the outcome of the election,” Jacob said.

“Our review of text, history, and frankly just common sense all confirmed the vice president’s first instinct on that point. There is no justifiable basis to conclude the vice president has that kind of authority,” Jacob testified.

On Jan 4. and Jan. 5, Jacob had several conversations with Eastman, as well as Trump and Pence chief of staff Marc Short, in which Eastman pushed the theory that Pence could either reject electors outright or delay certification for 10 days, giving state legislatures time to send Trump-friendly electors for a later vote count. Jacob was not swayed and worked to convince Eastman that his suggestions weren’t constitutional.

WATCH: Greg Jacob says Pence believed framers would not put election outcome in hands of 1 person

“The vice president never budged from the position that I have described as his first instinct,” Jacob testified.

The morning of Jan. 6, as Jacob and others polished Pence’s statement that he could not overturn the results of the election, Jacob said Pence received a phone call from the president. Though Pence stepped out to take it, the committee played testimony from others who heard Trump’s side of the call, including the president’s daughter, Ivanka Trump. They described it as heated, and said Trump used vulgar language to describe Pence.

Jacob also detailed Pence’s actions on Jan. 6, noting that the vice president was taken to a secure location as rioters stormed the building but never left the Capitol.

“The vice president did not want to take any chance that the world would see the vice president of the United States fleeing the U.S. Capitol. He was determined that we would complete the work that we had set out to do that day, that it was his constitutional duty to see it through,” Jacob said.

Jacob also said that Pence and his wife were frustrated that Trump never checked on their safety during the riot. And he testified that while they waited in the secure location, he read his Bible, relying on his faith to sustain him.

“Daniel 6 was where I went. And in Daniel 6, Daniel has become the second in command of Babylon, a pagan nation, that he completely, faithfully serves. He refuses an order from the King that he cannot follow, and he does his duty consistent with his oath to God,” Jacob testified.

“And I felt that that’s what had played out that day.”

For more on the key players in the Jan. 6 committee hearings, click here.