Hillary Clinton's weekend visit to the key primary state of New Hampshire has made one thing clear - her vote in 2002 to authorise the Iraq war will be the biggest obstacle to her winning the Democratic presidential nomination.
Mrs Clinton was dogged by questions on why she did not admit her vote had been a mistake. But she refused, saying only: "If I had known then what I know now, I wouldn't have voted that way." She then pinned the blame for the débâcle on President George Bush.
In a primary campaign where Democrat voters tend to be anti-war, this offers an opening to her two main opponents, senators Barack Obama and John Edwards. Mr Obama subtly kept up the pressure: "I will let her address past decisions and how she wants to move forward."
He turned to his advantage an attack on him by Australia's Prime Minister John Howard, who said terrorists would pray for a victory by Mr Obama, who has called for the withdrawal of US troops from Iraq by March 2008.
Mr Obama noted the US has nearly 140,000 troops in Iraq compared to the 1,400 Australians. "If he is ginned up to fight the good fight in Iraq, I'd suggest he calls up another 20,000 Australians and sends them to Iraq ... Otherwise it's just a bunch of empty rhetoric."