President Bush has taken a lead over Democrat John Kerry (search) among key groups such as Catholics and those with a high school education — largely because of voter doubts about Kerry, a poll suggests.

Bush was backed by 48 percent and Kerry by 40 percent among registered voters in the poll by the Pew Research Center for the People & the Press (search).

Bush has gained ground on Kerry, even though he has less of an advantage on who would be best in handling Iraq — now 46 percent for Bush to 38 percent for Kerry. Kerry inspires more confidence than the president on handling the economy and trails by 24 percentage points on handling terrorism.

The two are even among women and young adults. Bush has a 49-39 lead among Catholics, a 50-37 lead among those with a high-school education — groups that Kerry needs to win.

The poll of 948 registered voters was taken Sept. 22-26 and has a margin of sampling error of plus or minus 3.5 percentage points.