Politico reported Tuesday that although Michelle Obama has not always agreed with Clinton's politics, Obama admired how she raised her daughter in the public eye.

"Michelle may not have loved the (New York) senator, but she always respected how the Clintons raised Chelsea," said a person familiar with Clinton's end of the call. "They need to talk. There just aren't too many people who have shared that kind of experience."

Although Clinton was in a heated Democratic primary against Barack Obama, she later endorsed and actively campaigned for her former opponent, and that has strengthened the Clinton-Obama relationship, observers say.

"Senator Clinton did not just check the box for Obama -- she went all out for him, which says an awful lot about how important she felt this election was, what kind of character she has and the positive state of their relationship," said Chris Lehane, an aide to Democratic presidential nominees John Kerry and Al Gore.