Obama's top foreign policy adviser resigned last week after telling a British newspaper Clinton was "a monster."
"I don't think Geraldine Ferraro's comments have any place in our politics or in the Democratic Party. They are divisive," Obama told a Pennsylvania newspaper.
"I would expect that the same way those comments don't have a place in my campaign they shouldn't have a place in Senator Clinton's either," he said.
VOTER BLOCS
Exit polls in Mississippi showed Obama won about 90 percent of black voters, who were expected to make up about half of the state's Democratic primary electorate, and continued to hold big leads among young voters.
Clinton, a New York senator and former first lady, retained her advantage with older voters, exit polls showed. The two candidates have developed consistent bases of support within the Democratic Party.
Obama's win in Mississippi will add to his nearly insurmountable lead over Clinton in the pledged delegates who will help decide the nominee. Mississippi has 33 pledged delegates at stake.
But neither Obama nor Clinton is likely to reach the 2,025 delegates needed to clinch the nomination without help from nearly 800 "superdelegates" -- party officials and insiders free to back any candidate.
The states of Michigan and Florida, which were stripped of their delegates in a dispute with the national party and held unsanctioned contests won by Clinton, also could figure in a final resolution of the tight race.
Officials in both states have discussed redoing their contests so they would produce delegates to the convention, but the candidates, the state parties and national party would have to agree on the timing, funding and formats.
Clinton, who has repeatedly criticized Obama for failing to live up to his rhetoric, told supporters in Pennsylvania her rival's promises were not matched by his actions.
"My opponent is here in Pennsylvania talking about energy policy and I think specifically about wind energy and that's great," Clinton said.
"Except in 2005, when we had a chance to say 'no' to Dick Cheney and his energy bill, my opponent said 'yes' and voted for it with all of those tax subsidies," she said.
