In the early days of President’s Trump first term, when he signed an executive order to ban travel to the United States from seven Muslim-majority nations, Sen. Kamala Harris (D-CA) decided to get more information about the chaos occurring at airports across the country.

“So I called [then-Department of Homeland Security Secretary] John Kelly,” Harris writes in her new book, The Truths We Hold: An American Journey.

Senators talking to Cabinet members is not rare, especially when it involves a pressing legal and political matter. But Harris hadn’t called Kelly at his office. She had dialed him at home. And the soon-to-be chief of staff was not exactly pleased.

“There were a lot of ways Secretary Kelly could have shown responsiveness, a lot of information he could have provided,” Harris writes. “Indeed the American people had a right to this information, and, given my oversight role on the Senate Homeland Security Committee, I intended to get it. Instead, he said gruffly, “Why are you calling me at home with this?” That was his chief concern. By the time we got off the phone, it was clear that he didn’t understand the depth of what was going on. He said he’d get back to me, but he never did.”

Harris, who is contemplating a presidential campaign and who seems poised to use her book tour to test those waters, has made a name for herself sparring with Trump Cabinet officials. And she describes the conversation with Kelly as being both instructive for the way that things work in the nation’s capital and evidence that she had to do more to ensure that everyone who needed it had access to legal representation.

“I was new to Washington and still learning how things worked,” Harris writes. “This episode taught me that calling this secretary of homeland security was a wasted effort. We needed a law. The first bill I introduced in the Senate was the Access to Counsel Act, which prohibits federal officials from denying access to a lawyer for anyone detained trying to reach the United States.”

Harris has talked previously about the Kelly conversation, albeit with fewer details about how exactly the call went.

The Truths We Hold, which is being published as Harris begins a four-city book tour, offers readers a more composite view of her biography and policy prescriptions in advance of a likely 2020 presidential run. It is filled with stories about her upbringing, her history as a prosecutor in California and her brief but eventful time in the U.S. Senate so far.

Throughout the work, she explains how personal anecdotes have informed her policy views, such as the tragic story of her mother’s battle with colon cancer leading her to support Medicare for All. She also reveals how hotly she was pursued for another job opportunity that—had she accepted it—could very well have taken her out of elected politics and, with it, a possible presidential run.

In the summer of 2014, Harris writes, she got a call, this time at her home. It was from the Attorney General, Eric Holder, wondering if she had any interest in replacing him.

“He told me he had a question. ‘I’m going to be stepping down soon. Are you interested?’ It was, needless to say, a lot to take in,” Harris writes. “Did I want to be United States attorney general? Did I want to hold the office that Bobby Kennedy once held? Of course I did. This was the kind of job I used to daydream about during lectures in law school. And this wasn’t just any moment or any president. This was Barack Obama, my friend and my president, whose leadership I so admired and whom I had been so proud to support. To join his cabinet would have been the honor of my life. And yet I wasn’t sure if I truly wanted the job. By the time Holder stepped down, there would be fewer than two years left in the administration. What kind of opportunity would I have to create a real agenda?”

Harris would announce after that call that she intended to remain California attorney general. Two-and-a-half years later, she was in the Senate.