That development appears to be helping Sen. John Kerry, the presumptive Democratic presidential nominee. He wins the support of 51 percent of likely voters, compared to 46 percent for Bush. In February, Bush was ahead of Kerry by two percentage points. If Independent Ralph Nader is among the choices, Kerry gets 49 percent, Bush 44 percent and Nader 6 percent. Bush's overall job approval rating fell from 49 percent to 46 percent since the last CNN/Time poll on April 8, while his disapproval rating rose from 47 percent to 49 percent -- the first time that more people disapproved of...