From World Net Daily's report of the NOM co-sponsored event:

The two hot topics of abortion and same-sex marriage became even hotter when Luntz, as well as representatives from Focus on the Family and the National Organization for Marriage, questioned the candidates whether the issues were a matter for the states or whether AbrahamLincolnwas right in claiming, "States do not have the right to do wrong."

... Paul, however, pressed for constitutional limits on federal power, arguing, "States definitely have the right to be wrong," and that he would be "very cautious about nationalizing things."

... Brian Brown, president of the National Organization for Marriage, at one point asked the candidates point blank if they would support a constitutional amendment defining marriage as between one man and one woman.

"No," Paul answered succinctly.