Voting for someone on the basis of their sex is just as stupid as voting for someone on the basis of their race/skin-colour. You should be voting on the basis of their policies — far more complex than some genetic attribute.
Not stupid, logical.
Politicians are perceived to lie and break promises on a regular base, you don't know what to expect.
Then it is logical to vote on persistent attributes.
In any case, would Clinton have won your vote on Clinton would have the most political impact itself, women as president.