When you consider that Hispanics are nearly 100% Catholic or Evangelical, and are strongly pro-Obama (except for the Cubans), McCain’s lead among non-Hispanic Catholics must be very large.
From a thread about the 2004 election results:
An important division exists between white and minority Catholics, particularly Hispanic Catholics. While they are a swing group overall, white Catholics voted decidedly for George W. Bush in 2004, 56 percent to 43 percent, and Hispanic Catholics strongly supported John Kerry, voting 65 percent to 33 percent in his favor. In this year's exit poll, Hispanics made up 17 percent of Catholics, a jump of 4 percent from 2000. It will be interesting to see if this rift deepens over time as the makeup of the American Catholic church continues to change.