SACRAMENTO, Calif. - For more than a decade, Gov. Arnold Schwarzenegger managed to keep secret the fact that he had fathered a child with a member of his household staff, misleading not only his family but also millions of Californians who might not have elected him had they known.

Battered by years of fiscal problems, Schwarzenegger's public approval rating had dipped to 23 percent when he left office in January. On his final day in office, he shortened the manslaughter sentence for the son of his political friend Fabian Nunez, angering his shrunken pool of supporters. If that had not already ruled out any political future, his acknowledgment Tuesday almost surely did.

"This layered on top of the Nunez thing pretty much means his political future is done at this point," said Republican strategist Jeff Randle.

In the months since leaving office, Schwarzenegger has traveled extensively in Europe and South America, negotiated movie and TV deals, and been mentioned as a possible federal appointee.

He and wife Maria Shriver announced last week that they were separating but gave no reason. Shriver moved out of their home in Los Angeles' Brentwood neighborhood earlier this year, after Schwarzenegger acknowledged having a child with a household employee.

"This is a painful and heartbreaking time," Shriver said in a statement. "As a mother, my concern is for the children. I ask for compassion, respect and privacy as my children and I try to rebuild our lives and heal. I will have no further comment."

It was Shriver who defended her movie-star husband against accusations he groped women late in his 2003 campaign, a defense that friend Barbara O'Connor said Shriver would not have provided had she known.

"She staked her whole life on her husband and her family," said O'Connor, professor emeritus of communication at California State University, Sacramento. "This has to be her worst nightmare."

Schwarzenegger apologized in a statement Tuesday.

"After leaving the Governor's office I told my wife about this event, which occurred over a decade ago," Schwarzenegger said. "I understand and deserve the feelings of anger and disappointment among my friends and family. There are no excuses and I take full responsibility for the hurt I have caused. I have apologized to Maria, my children and my family. I am truly sorry.

"I ask that the media respect my wife and children through this extremely difficult time. While I deserve your attention and criticism my family does not."

Shriver, niece of President John F. Kennedy, left her career as a journalist at NBC News when Schwarzenegger was elected. She became one of the most visible first ladies in recent California history. "She gave up her career, and was probably the best first lady I've seen in the 40 years I've been in Sacramento," O'Connor said.

Two of the couple's four children, Katherine, 21, and Patrick, 17, posted messages on Twitter on Tuesday. "This is definitely not easy but I appreciate your love and support as I begin to heal and move forward in life," Katherine wrote.

Patrick wrote, "Some days you feel like s-, some days you want to quit and just be normal for a bit," quoting the band Fort Minor's heartbreak song "Where'd You Go." Adding his own words, he said: "Yet i love my family till death do us apart."

O'Connor said she thought Schwarzenegger "genuinely loved Maria, and she him."

"It's just very sad. I think everybody feels sadness."