After months of speeches and debates, and nearly $1 billion in total campaign spending to date, the presidential race is a dead heat. A head-to-head showdown between Sens. John McCain and Barack Obama is now too close to call — 45.9 percent to 44.6 percent — based on an averaging of national polls by realclearpolitics.com. A head-to-head showdown between McCain and Sen. Hillary Rodham Clinton is also razor-thin, 46 percent to 45.7 percent. Now, a poll of likely Christian voters offers evidence of why the McCain campaign is struggling to gain real traction and a lead that can last. The...