SOme opposition is that it will cause protectionist pratices such as women being exempt from the draft to be erridicated.
SOme women fear such things as unisex bathrooms.
The addition of the amendment to the Constitiution would cause gender to be a suspect classification like race and therefore would lead to seperate but equal accomidations to be deemed unconstitutional. However, it seems to me that this amendment is necessary if women are to overcome thousands of years of discrimination and treatment as second class citizens. And everything depends on how the courts and ultimately the supreme court interpret the amendment. I hope this is helpful and insightful to someone. Net sm .