Anyone know when Republicans started dominating white guy vote? Nixon era?
Probably before then. It's kinda complicated because for most demographic groups there isn't much of a gender gap *at all*... but there has tended to be one amoungst high income types
How much of that is related to lifestyle choice? I have some vague recollection that married white women are basically as Republican as their male counterparts, but there's a sizeable gap between unmarried white men and women.
Yes married women are much more republican than single women. Married women tend to be more financially secure, have less want for abortions (lots of exceptions on this one), and are more likely to have guns in the home (because men own guns at higher rates than women).