It takes women fewer alcoholic drinks to get drunk than it does men. This is because of a number of reasons, such as the fact that the average woman weighs less than the average man and the fact that women have more body fat than men.
I'm surprised that the ACLU or other feminist litigators have not sued to have DUI laws struck down under the 14th Amendment. Since DUI laws prohibit driving while having a blood alcohol content above a certain level and it takes women fewer drinks to reach that level, the government is discriminating against women by requiring them to drink fewer alcoholic drinks than men in order to be able to drive without (possibly) being arrested.
Sure, the idea that BAC limits constitute gender discrimination may sound ludicrous. But consider that the branches of the United States military have more lenient physical standards for women than men. In similar fields, such as police, firefighting, and corrections departments, height standards have been eliminated due to their discriminatory nature. In many cases, especially police departments, physical standards have been made "gender neutral" - meaning in order to allow for an acceptable number of women to pass their physical tests without resorting to different physical standards by gender, the tests have been made so easy that any man in better shape than a WoW player is capable of passing.
Now, I am not a true believer in the typical conservative mantras that the military "protects our freedom" and the police are always looking out for us, but physical performance is essential to jobs in such organizations, those organizations are a necessary part of any safe and functional society, and watering down standards for women in such organizations is dangerous. If it is okay for the military to hold women to lesser physical standards and for police to water down their tests in the name of Equality, then surely it would be okay for states to allow women to drive with a higher blood alcohol content then men so they can have the same number of beers as men, because it is clear that Equality trumps society's safety.