Bill Clinton’s appearance on “The Oprah Winfrey Show” Tuesday was ostensibly to promote his new book “Giving.” But observers couldn’t help wondering if he’s also ratcheting up his support for wife Hillary’s presidential campaign.

Clinton’s appearance came just two weeks after the release of a NewsMax/Zogby poll revealing that 81 percent of likely Democratic caucus-goers in Iowa believe the former president would have a positive effect on a Hillary Clinton administration. The figure was even higher – 84 percent – among women respondents.

And 77 percent of those polled said that if a Democrat wins the White House next year, they would prefer a return to the domestic and foreign policies of the Bill Clinton presidency.

Also telling is that Bill spent the Labor Day weekend stumping with Hillary in early primary and caucus states Iowa and New Hampshire.

Add to the mix that the Wall Street Journal ran a story on Tuesday headlined: “Hillary Clinton Eases Her Husband Into the Campaign Limelight.”

On Tuesday’s show, Clinton acknowledged to Oprah – who has come out in support of Hillary rival Barack Obama – that he’s involved in his wife’s campaign, but said it was not in an official manner.

“I’m still sort of in politics because Hillary’s in politics, but I’m glad it’s her instead of me,” he said.

Clinton also discussed his foundation and his post-White House efforts to battle urgent problems including poverty, global warming, childhood obesity and the spread of HIV/AIDS.

His appearance on Oprah’s show featured a dramatic moment involving Clinton and a young girl named Kendall Ciesemier.

When Kendall was 11 years old, she responded to a campaign launched by Oprah and spent $360 of her own money to adopt an AIDS orphan.

Not long after, Kendall – born with a rare liver disease – had to undergo two liver transplants. From her hospital bed, she asked people not to send her flowers and gifts but instead to donate money to children in Africa.

Kendall founded her own organization, Kids Caring 4 Kids, and has raised more than $100,000.

On Tuesday, Clinton went to Kendall’s high school in Illinois and asked her to join him on Oprah’s show. The girl sat between Clinton and Oprah, who called her a “shining light for the rest of the world.”

Then after a commercial break, Clinton told Kendall: “The man who came here with me today – who absolutely forbade me to use his name because he wants to be anonymous – wants me to tell you that he is going to give you half a million dollars.”

The audience erupted with applause.

Clinton’s book “Giving: How Each of Us Can Change the World” went on sale Tuesday.