Michelle Obama has had testy relationships with some top White House advisers, and at times pushed the president to pursue politically difficult causes like healthcare and immigration reform, according to a new book.
The Obamas by New York Times reporter Jodi Kantor, paints Mrs. Obama as "an expert motivator and charmer" and "an increasingly canny political player" ahead of the 2012 presidential election, expected to be a tough fight for her husband, president Barack Obama.
Mrs Obama fought against political tactics espoused by Rahm Emanuel, her husband's former chief of staff, and Robert Gibbs, the former White House press secretary, the book said, pushing her husband to replace advisers who she felt were "too insular, not strategic enough," according to excerpts from the book on the newspaper's website.
"'She feels as if our rudder isn't set right,'" the book quotes Barack Obama as telling aides.
The Obamas did not speak to Ms Kantor for the book, which was based on interviews with more than 30 current and former staff members. It will be released Tuesday.
The White House yesterday called the book "an overdramatisation of old news" and said Ms Kantor had not spoken to the Obamas since 2009.
"The emotions, thoughts and private moments described in the book, though often seemingly ascribed to the president and first lady, reflect little more than the author's own thoughts," said Eric Schultz, a White House spokesman.
The book says Mrs Obama, known for her campaign to promote healthy eating and exercise, initially sought a low-key role in the White House, and even considered postponing her move to Washington from Chicago after the 2008 election.
She was worried about being the first African-American first lady, and felt "everyone was waiting for a black woman to make a mistake," said a former aide quoted in the book.
Tensions arose between Mrs Obama and Mr Gibbs, who worried about public missteps. Valerie Jarrett, senior adviser to the president and a friend of the couple, tried to moderate, the book said.
Mrs Obama supported her husband's "instincts for ambitious but unpopular initiatives like the overhaul of health care and immigration laws, casting herself as a foil to aides more intent on preserving congressional seats and poll numbers," the excerpts say.
"She does think there are worse things than losing an election," said Susan Sher, her former chief of staff, in the book. "Being true to yourself, for her, is definitely more important."