Barack Obama proposed to a woman who rejected him not once but twice ... before he met Michelle -- this according to a new biography.

The woman is Sheila Miyoshi Jager. David Garrow, author of the new book, "Rising Star: The Making of Barack Obama," says Obama met Jager in the mid-'80s when he was doing community organizing in Chicago.

Jager, of Dutch and Japanese ancestry, told Garrow even back then, Obama had a strong belief he'd someday become President of the United States. She also told the author Obama had "a deep-seated need to be loved and admired."

She says in 1986 Obama asked her to marry him, but her parents were opposed because they thought she was too young. She said no, but they continued dating.

Then, Garrow says, Obama's presidential ambitions became a centerpiece of their relationship, causing a conflict because he worried a non-African-American spouse would do him political damage.

Garrow says he "felt trapped between the woman he loved and the destiny he knew was his."

Obama went to Harvard Law School in 1988 and the relationship was on the ropes, but Jager says Obama again asked her to marry him before he left, but she was off on a research trip to Seoul and rejected his proposal.

Obama fell for Michelle after their first year in law school but, according to Garrow, he was still occasionally seeing Jager.