Think Progress has done an analysis of why raising the minimum wage from the current $7.25 an hour to $9 an hour by 2015 is so important to women. Not only are the majority of people earning the minimum wage women (64%), they are also the primary or co-breadwinner for the family (60%).
Not surprisingly, the Rethuglican leadership in Congress is calling the President's proposal to raise the minimum wage a non-starter. They've never accepted women in the workforce, and never been willing to give equal pay for equal work (see Lily Ledbetter Act). It's another example of their war on women, which is based on a nasty fundamentalist, right wing creed that scorns working women, blames them for rape, and refuses to protect them against violence or unwanted pregnancies.