They appear to be begging the question. The statutes in question do not say that drinking negates consent, they say that it is rape if someone is too drunk to consent. You have to look at precedent to try to determine what constitutes "too drunk to consent". It is not a simple case of "oh I was drinking so nothing I say counts" as some like to portray. The law has to be careful because claiming "I was drunk" to get out of consent would also have significant repercussions on other cases, not just rape.