Double Standard in Vitter and Craig Sexual Misconduct Cases?

Double standard?  Sen. Larry Craig (R-ID) committed a crime when he solicited an undercover cop for sex in a Minneapolis public restroom.  Republicans immediately distanced themselves from him and called for his resignation.  Sen. David Vitter (R-LA) also committed a crime when he solicited and engaged in sexual activity with prostitutes in Washington DC and Louisiana on multiple occasions.  Republicans have supported him and not called for his resignation.  Are Republicans supporting Vitter and denouncing Craig because Vitter's misconduct involved heterosexual activity and Craig's misconduct involved homosexual activity?  You decide.