Increased level of education and focus on careers--as women have the ability to have relationships but also provide for themselves, marriage is not a necessary option.
Birth control and access to college education has allowed women to focus on careers instead of family. They are able to still have successful lives but not have to worry about balancing a career and a family.
There is always one cabinet member left behind in a secure facility in case there is a catastrophic attack during the State of the Union. The member left behind is in the line of succession and therefore will lead the country and rebuild the Government after the attack.