FRIDAY, APRIL 20: While President Obama maintains a slim edge overall against Mitt Romney, the presumptive GOP nominee holds a huge lead among white evangelicals and Roman Catholics, according to a new poll.

 Obama lost ground in the past month to Romney among Protestants and Catholics generally, according to a poll released Tuesday by the Pew Research Centre for the People and the Press.

Obama's support has dropped among Protestants (five percentage points) and Catholics (eight percentage points) since mid-March.

 Romney now possesses a particularly large lead over Obama among white evangelicals (73 to 20 per cent) and white Catholics (57 to 37 per cent).

Religiously-unaffiliated Americans largely support Obama (67 to 26 per cent).

 Americans who attend religious services weekly favour Romney (56 to 38 per cent) while those who attend less often support Obama (56 to 37 per cent).

 In 2008, Obama won Catholic voters overall, reversing recent trends, and made small inroads among evangelicals, three-quarters of whom still backed GOP nominee John McCain.

 Hot-button issues such as abortion and same-sex marriage have not played significant roles thus far in the 2012 campaign, but the faith of particular candidates — particularly Romney’s Mormonism — emerged as an early flash point.

 Now, nine in 10 white evangelicals say they support Romney, with 84 per cent saying there is no chance they will change their mind, according to the Pew poll.

 Meanwhile, the nation’s Catholic bishops have waged a high-profile battle with the Obama administration over a new federal mandate requiring employers to offer birth control coverage to employees.

Though Obama has promised exemptions for religious groups, the bishops call the mandate an affront to religious liberty, and prominent evangelicals have rallied to their side.

 While Obama’s overall advantage has narrowed since March, when he held a 12-point lead, the Pew pollsters said “there is little to suggest a specific problem or campaign event as having a critical effect”.

 Obama holds a large lead (56 to 37 per cent) among voters who say birth control is a very important issue.

In general, however, social issues are a low priority for most Americans, according to Pew, with more than 80 per cent listing the economy and jobs as the concerns that will determine their vote in November.