I think it is because the United States has been laboring under the veil of a Pauline religion that places women in a role subservient to men. Even women of the church say that the Bible says "the man is head of the household and the woman is his helpmeet," whatever that is supposed to mean. However, that has been interpreted to mean that the woman plays a secondary role, keeping house, raising the children, etc. Statistically speaking, even in American households where the woman and mother has a career or holds a job, she is still responsible for most of the household drudgery while the “head of the household” watches sports on TV or plays golf.
In 1982 The Equal Rights Amendment was introduced for a Constitutional Amendment assuring women equal rights to men, but it has never been ratified. It has been introduced into every Congress since 1982, but 15 states still hold out for the ratification needed to make it a constitutional amendment. Why? Again when you look at the states involved, most of them are in the Bible Belt.
With a few exceptions, the Europeans are not known for their religious culture any longer. Perhaps it is because a war-decimated continent has rebuilt itself upon its own strengths. Even Israel , with Golda Meir as one of its founders, is not under the influence of a Pauline deity, nor is Germany or Great Britain. When a woman in this country becomes involved in politics, she becomes the target of ridicule, even by other women. Take Hillary, for instance. She is a strong woman with both national and international experience, which probably makes her more qualified to run this country than any of the men running. However, look what “they” are doing to her. Whether or not she was doing anything wrong is not the point. She is perceived as doing wrong. Americans are serving as judge and jury by subscribing to rumors and not knowing the facts.
On the other hand, as the warts are brought out against the male candidates who have announced a run for the presidency, they are quickly forgiven and forgotten. Women should support other women, and that includes qualified female candidates but American women have a tendency to put other women down. Until Americans get rid of this concept that a woman’s place is to serve her man, we are unlikely to see many women in leadership capacities.