I looked at the time series of polls concerning support for gay marriage in the USA
http://graphics8.nytimes.com/images/2013/03/26/us/politics/fivethirtyeight-0326-marriage2/fivethirtyeight-0326-marriage2-blog480.pngI saw that the share of the people who supported gay marriage in the USA was very low in the mid-1990s. It increased until 2000. Than, there was a stagnation. The support for gay marriage started to increase again only in 2004, and then, it has been continuosly increasing until now.
Do you think that the 9/11 could be one of the causes of the stagnation that occured between 2000 and 2004? I know that the islamic fundamentalist terrorists were not gay married. But, maybe, this attack could have created a conservative wave in the public opinion. It could have made the christian fundamentalists stronger.