In supporting gay marriage, former first lady Laura Bush splits with her husband.

In an interview Tuesday with CNN's Larry King, Bush said she disagreed on gay marriage with her husband, former President George W. Bush.

“There are a lot of people who have trouble coming to terms with that because they see marriage as traditionally between a man and a woman,” she told King. “But I also know that, you know, when couples are committed to each other, that they ought to have, I think, the same sort of rights that everyone has.”

When asked, “You think [legalization of gay marriage] is coming?” Bush replied, “Yeah, that will come, I think.”

Bush first spoke about gay marriage in her 456-page memoir Spoken From The Heart, which was released last Tuesday.

The book's description says: “With deft humor and a sharp eye, Laura Bush lifts the curtain on what really happens inside the White House, from presidential finances to the 175-year-old tradition of separate bedrooms for presidents and their wives to the antics of some White House guests and even a few members of Congress.”

In the book, Laura Bush describes how she urged the president not to make gay marriage a significant issue in 2004.

“In 2004 the social question that animated the campaign was gay marriage,” Bush writes. “Before the election season had unfolded, I had talked to George about not making gay marriage a significant issue. We have, I reminded him, a number of close friends who are gay or whose children are gay. But at that moment I could never have imagined what path this issue would take and where it would lead.”

Citing historical reasons, then-President Bush endorsed a constitutional amendment that would restrict marriage to a heterosexual union but leave open the possibility that states could allow civil unions.

“Marriage cannot be severed from its cultural, religious and natural roots without weakening the good influence of society,” he said in 2004.

The year was pivotal for the gay marriage movement. The president's endorsement came after Massachusetts became the first state to legalize the institution and San Francisco's Mayor Gavin Newsom decided to give marriage licenses to gay and lesbian couples. Proposition 8 – California's gay marriage ban approved by voters in 2008 – was the eventual fallout of Newsom's decision.

Carrie Gordon Earll, a spokeswoman for Focus on the Family, a group opposed to gay rights, denounced Laura Bush's position on gay marriage, calling it “disappointing.”

Laura Bush is the most recent wife of a high-profile Republican to back gay marriage. Arizona Senator John McCain's wife, Cindy McCain, has also split with her husband on the issue.