US President Barack Obama has warned Congress that more Americans will die if it does not act now on health care, seizing the spotlight at a pivotal moment for his embattled reform drive. In a rare joint address to Congress that marked the biggest test of his leadership so far, Mr Obama bluntly warned he would not waste time working with Republicans bent on defeating his plan to damage him politically. "I am not the first president to take up this cause, but I am determined to be the last," Mr Obama said. Months of charges by conservatives that he...