In an excerpt from his upcoming memoir, A Promised Land, the 59-year-old politician admits that he could "sense an undercurrent of tension" in his wife.
"Despite Michelle's success and popularity, I continued to sense an undercurrent of tension in her, subtle but constant, like the faint thrum of a hidden machine," an excerpt posted by CNN on Thursday reads. "It was as if, confined as we were within the walls of the White House, all her previous sources of frustration became more concentrated, more vivid, whether it was my round the clock absorption with work, or the way politics exposed our family to scrutiny and attacks, or the tendency of even friends and family members to treat her role as secondary in importance."
Barack -- who shares daughters Malia and Sasha with the former first lady -- also writes that there were nights "lying next to Michelle in the dark, I'd think about those days when everything between us felt lighter, when her smile was more constant and our love less encumbered, and my heart would suddenly tighten at the thought that those days might not return."
A Promised Land will be released on Nov. 17. The book follows Michelle's own memoir, Becoming, which she released in 2018. In it, she also touched on her marriage and being the first lady of the United States.
Michelle's book explored everything from meeting Barack, dating, getting married and their infertility struggles. She called their trouble with starting a family "as surprising as it was disappointing," even admitting that for a while she assumed that their conflicting schedules were to blame.
"Our attempts at procreation took place not in service of important monthly hormonal markers but rather in concert with the Illinois legislative schedule. This, I figured, was one thing we could try to fix," she wrote. "But our adjustments didn’t work, even with Barack flooring it up the interstate after a late vote so that he could hit my ovulation window and even after the Senate went into its summer recess and he was home and available full-time."
Meanwhile, during an appearance on Conanin September, Michelle joked that her husband had "limited time to get on my nerves" during quarantine since he was busy finishing up his upcoming book.
"He's sort of gotten on my nerves because I haven't seen him enough," she quipped, adding, "He can't win."