Democratic rivals slog it out
Updated on 22 April 2008
There are fears that the mudslinging between Barack Obama and Hillary Clinton could dent the Democrats' presidential chances.
Hillary Clinton has warned that America would be able to "obliterate" Iran if it launched a nuclear attack on Israel.
It is a sign of how badly she needs to win - and win big - in today's Pennsylvania primary, the biggest prize left in the race for the Democratic nomination for the
White House.
So much is at stake that Clinton and her rival, Barack Obama, have been laying into each other with increasingly negative attacks. And party leaders are worried the mud could stick.
