Months before the first ads would run on Proposition 8, San Francisco Catholic Archbishop George Niederauer reached out to a group he knew well, Mormons.
The June letter from Niederauer drew in the Church of Jesus Christ of Latter-day Saints and proved to be a critical move in building a multi-religious coalition.
But it started long before that, note the KofC contribution on Jan 30, 2008. (From the S.F. Chronicle list of contributors for and against Prop 8 )