> that women have a right to do what they want with their own body

This is not much different, since as a non-sentient individual, the fertilized egg is a part of the woman's body. I can't speak for others, but I certainly look for the line when a foetus becomes a "person."

I'd like to see some surveys on how many Americans support abortions in which terms and why, but haven't found any.

> that abortion has social benefits

This is a supporting argument only relevant when the underlying action is ethical.

Executing stupid people may have social benefits, but it is not ethical.