The pulpit has become a potent political weapon in America's closest election race in decades. President Bill Clinton formally waded into the campaign to support Vice-President Al Gore by visiting two prominent black churches in Washington on Sunday, urging the congregations to 'get out to vote'. Mr Gore has also been invoking religious symbolism recently, saying prayer was one of his chief recreations. He also visited the hi-tech Potter House Sanctuary Church in Dallas, the Texas heartland of his Republican rival, George W. Bush. As hundreds of believers called up their favourite prayers on special in-house Palm Pilots, the Democratic hopeful called for more compassion and respect for the family. 'I will also fight the cultural pollution that is undermining family life,' Mr Gore said in a speech that followed a sermon by arch-conservative Pat Robertson. American leaders - including Mr Clinton - have generally observed the tradition of separating the church from state while in office. But the campaign trail is another matter. Both campaigns privately acknowledge that they are keen to appeal to an American population that is growing not just increasingly religious, but more fundamentalist as well. Mr Gore regularly describes himself as 'born again', while Mr Bush tells campaign rallies of 'opening my heart to Jesus Christ', who he has described as his favourite philosopher. However, one politician who is moving in the other direction is former president Jimmy Carter. With no campaign to run, Mr Carter recently said he would distance himself from the giant Southern Baptist church after a lifelong devotion. Mr Carter said he was worried the church - which boasts 16 million followers - was moving away from its traditional roots with 'rigid' new policies. He said he could not accept its refusal to acknowledge female priests, nor an edict for wives to 'graciously submit' to their husbands. Meanwhile, the latest polls confirm that neither campaign can afford to isolate any minority or faction as the race remains tight with only a week to go. Leading pollster John Zogby's Reuters/MSNBC tracking poll suggests Mr Bush has solidified his lead to three points over Mr Gore. However, the poll carries a three per cent margin of error. Polls across nine potential swing states suggest Mr Bush may face trouble in the all-important electoral college. The Reuters poll suggests Mr Gore could win 87 out of 153 college votes up for grabs across the swing states. A total of 270 electoral college votes out of 538 are needed to win.