The poll, conducted by the Wall Street Journal, is the latest to indicate a slump in public support for the US leader as his Republican party heads into the campaign for mid-term elections in November. In the poll, released in the newspaper's online edition, Bush has lost six percentage points in a month. Iraq remains the main concern. Twenty-eight percent of Americans say it is one of the two most important topics, up from 23 percent in April, followed by IMMIGRATION (16 percent) and the price of petrol (gasoline) (14 percent). Only 24 percent of the 1,003 people asked between...