Mainstream culture has not changed on abortion, yet there was a vote.
Two votes.
That's really not a good argument. Abortion and marriage aren't like things. Abortion is undesirable, a necessary evil, something that should be safe and rare.
I think most people oppose abortion, but respect the right of women to choose. They also recognize medical reasons for abortion.
Change abortion to marriage, or gay marriage, or interracial marriage:
"I think most people oppose marriage /gay marriage / interracial marriage, but respect the right of women to choose. They also recognize medical reasons for marriage /gay marriage / interracial marriage."
That doesn't work..
Also, my impression is the old school liberals who favored Roe weren't really enthusiastic about marriage equality..
euthanasia is another one like abortion..