Smoking pot is illegal. Gambling is not, at least in Atlantic City and Vegas.
Premarital sex is condemned by all three of the major religions, and there are scriptural references to back it up. So even if you disagree, you can hardly accuse Bennett of trying to impose his personal moral code on anyone by saying that premarital sex is immoral.
Do you honestly think that if pot were legalized Bennett would then automatically change his position on the issue, ceasing to label it 'immoral'? It has nothing to do with legality.