I expected it all to start after the primaries (that would be the norm):

http://elections.foxnews.com/2008/05/13/pastor-hagee-apologizes-for-anti-catholic-remarks/

Although, in this case, I don't think McCain attended his church for 20 years. I could be wrong, we'll see. And McCain has denounced his comments:

McCain, who has taken pains to gain the trust of the religious right, has rejected specific statements from Hagee — namely about the Catholic Church and blaming the sinful behavior of New Orleans residents for Hurricane Katrina — but would not denounce the pastor. Hagee apologized for the Katrina statements a couple weeks ago, saying it’s not his place to try to know the mind of God concerning the natural disaster.

Probably a case of trying to hold on to or gain the support of the far right without being associated too closely with it.