Since he took office in January, President Barack Obama has made clear that he views this year as the best opportunity in decades to overhaul the nation's ailing health-care system; more recently he has stressed that he wants the House and Senate to pass their respective bills before their month-long August recess. That, to say the least, is not going according to plan. The Senate said last week it will not make this deadline and the House is also looking increasingly unlikely to produce a bill by then. This slows the momentum behind the President's top priority, giving opponents extra time to sow doubts in both politicians and the public. But it also raises the question: Why can't a popular President with poll numbers in the 60s and super majorities in both chambers of Congress get this done? Here are the five biggest hurdles to health-care reform.