Hillary Clinton leads Barack Obama 47 percent to 40 percent in an AP-Ipsos poll conducted April 30 – May 4. The margin of error is 4.3 percent. In general election match-ups, Clinton leads John McCain 47 percent to 42 percent with 8 percent saying neither and Obama leads him 46 percent to 42 percent with 9 percent saying neither. The margin of error is 3.1 percent.