The two top candidates for the Democratic Party nomination for the US presidency emphasized their differences during a debate in California.
Illinois Senator Barack Obama and New York Senator (and former first lady) Hillary Clinton exchanged their views Thursday on national security, the mortgage crisis and other issues.
On health care, Clinton advocated a mandatory universal insurance plan that she says will lower costs, while Obama recommended a voluntary system.
They were left as the two top contenders for the Democratic presidential nomination after former North Carolina Senator John Edwards ended his campaign.
Earlier Thursday, California Governor Arnold Schwarzenegger endorsed fellow
Republican Arizona Senator John McCain for the US presidency.
At an event in Los Angeles, Schwarzenegger praised McCain as an extraordinary leader who can work with political rivals.
The endorsement could help McCain pull further ahead of the other top Republican candidate, former Massachusetts Governor Mitt Romney.
McCain also won the endorsement of former New York City Mayor Rudy Giuliani, who ended his own campaign Wednesday
A multi-state round of voting dubbed "Super Tuesday" is next week, when more than 20 states hold primaries or caucuses.