US Presidential elections are dominated by two corporate-corrupted political parties, largely because the US has a screwed up voting system where there are only allowed to be two candidates with one vote per person, and so there is a prevailing logic that any candidate must be from those two political parties. Those parties being corrupt, they tend to pick their candidates not on the basis of being good people for the job, but due to opaque political considerations.
Those parties have offered very few female choices, partly because the USA also has strong sexist elements, and the sophistication of the conversations around its elections are horrifyingly crude and stupid.
Shirley Chisholm ran but was not chosen by the Democrats. In 1972, racism and sexism were stronger than in recent decades.
When Geraldine Ferraro was a Vice Presidential candidate, she didn’t win, but at least she was intelligent and competent.
When Sarah Palin was a Vice Presidential candidate, it marked a low point at the time in the intelligence of US politics, as someone who didn’t know basic world geography or other basic facts was allowed to be the VP candidate.
Now we have Hilary Clinton as a potential candidate, and I think in theory she might be electable, but unfortunately she is clearly not an honest candidate for change and for the people the way Bernie Sanders is. Also, many people hate her for a variety of reasons, only some of which are sexist.