Women vote based on consensus.
As a consensus develops, others glom on.
Then there is the Oil of Olay effect. A good pitchman can sell them anything
Women vote more on the basis of race and ethnicity. Obama won the black women's vote 96% to 3%. He won the Latina vote 76% to 23% and other (including Asian) 66% to 31%.
Romney won the white women's vote 56% to 42%. Romney also won the married women's vote 53% to 46%. Obama won the single woman's vote 67% to 31% and the single male vote 56% to 40%.
The War on Women stratagem seems to only work on certain segments of women. Gender doesn't appear to play as big a role as race, ethnicity, and marital status.