Former President Barack Obama ditched plans to marry a white girlfriend because he was worried the interracial relationship would hold back his political ambitions, according to a forthcoming biography of the former president.

The biography, “Rising Star: The Making of Barack Obama,” was written by Pulitzer Prize-winning author David Garrow and is set to come out on May 9. The Daily Caller has previously reported how the book states that a young Obama “considered gayness.”

The book reveals how Obama had lofty political ambitions as a young man confiding in people that he wanted to be mayor of Chicago or a U.S. senator. The former president also told one of his first girlfriends, Sheila Miyoshi Jager, that he wanted to be president one day, and spoke about this happening as a “destiny.”

Jager, like Obama was mixed-race, as she was half-Japanese and half-Dutch. The two lived together in Chicago and in the winter of 1986 when Obama was 25 he proposed to Jager, according to Garrow’s book. Jager’s father later met Obama and said that he wasn’t sure if Obama could support her and Jager decided that they shouldn’t get married “yet.”

The next year in the spring of 1987, the two would argue a lot about the racial dynamics of their relationship. Garrow wrote that Jager said “over the course of spring ’87, [Obama] changed-brooding, quiet, distant-and it was only then, as I recall, that he began to talk about going into politics and race became a big issue between us.”

According to the book, Jager described that the “resolution of his ‘black’ identity was directly linked to his decision to pursue a political career.” The biography describes how having an interracial marriage in Chicago was detrimental to one’s political prospects.

Garrow wrote that an Illinois state senator, Richard H. Newhouse, had difficulty because he had a white wife. “Across the South Side, the word on the street was that Newhouse ‘talks black but sleeps white,’ and one black nationalist explained that “the perception now is that an African-American married to a white is unable to give 100 percent to the cause.”

It was these concerns that led Obama to decide not to continue his pursuit of marriage with Jager. A close friend of Jager’s, Mike Dees, recalled that Obama was “concerned if he was going to take the steps to the presidency with a white wife.”

Garrow wrote, “Barack ‘was very drawn to her, they were very close,’ yet he felt trapped between the woman he loved and the destiny he knew was his.”

Jager is now a professor of East Asian Studies at Oberlin College, while Obama fulfilled his “destiny.”

Garretson Carter contributed reporting.

“Rising Star: The Making of Barack Obama” — $27.28 Hardcover, $30.59 Paperback, $24.99 Kindle