I do not think women should be allowed to be presidential nominees because I, like most of the electorate I assume, vote based on which of the candidates I imagine as the bottom in a hypothetical gay relationship between them. I would love to one day see a woman president, and I fully support them inheriting the duties through the line of succession, but it is too dangerous to mess with the electoral process.
I believe for that to work we would first need a comprehensive education campaigning about the dynamics of lesbian relationships, we can not risk confusing the electorate and ending up with another 2016 election.