Do you have a cite for that? I find that very hard to believe.
GALLUP NEWS SERVICE: “And in 1960, men sided with Democrat John F. Kennedy by 4 points, 52% to 48%, and women backed Republican Richard Nixon by 2 points, 51% to 49%.
“Prior to 1964, women tended to vote more Republican than did men.”
http://www.gallup.com/poll/2884/big-gender-gap-distinguishes-election-2000.aspx