The best areas of the country for women's representation in elected office are the Pacific and New England regions, while the South and Middle Atlantic continue to fall behind.
Part of this discrepancy may have to do with how likely these regions are to vote Democratic. Fifteen of the 17 states with Gender Parity Scores of C or above either voted for Hillary Clinton in the 2016 Presidential election or currently have two Democratic senators, a fact that reinforces the extent to which Republican women are underrepresented in our government.
According to our Gender Parity Index Report for 2018, there is a correlation between women's representation and geographic location. The states ranked in the bottom ten GPIs are generally clustered in the Southeast and Mountain West. The majority of states with top ten GPIs are located on the West Coast.
Women's representation is not entirely dependent on geography or partisanship, but these two factors - which are highly correlated with each other - both play an important role.