Obama, the presumptive Democratic presidential nominee, says he will stress differences between himself and presumptive Republican nominee John McCain, especially on issues such as healthcare, abortion and judicial appointments.
Female voters will respond positively to Obama's message, campaign spokeswoman Linda Douglass told USA Today. The gender gap in the primaries -- Clinton consistently won women voters -- wasn't anti-Obama, but pro-Clinton, she explained.
"I don't think it was about him," Douglass said, "it was about her."
Still, observers said, winning that support won't be easily, since many of Clinton's supporters said they think the U.S. senator from New York was treated disrespectfully during the primary, the newspaper said.
"Barack needs to reach out to many of these women," says Sen. Claire McCaskill, D-Mo., an Obama supporter.
Some Clinton supporters wonder when a woman will be U.S. president.
"If not her, who?" asked says Sky Underwood, 57, a New York designer who volunteered for Clinton. "If not now, when?"