Yank
Bulbous Also Tapered
The argument seems to be that, as it doesn't appear in the Constitution, it cannot possibly be a constitutional right. But then, a lot of things don't appear in a document written in the late 18th century!
At the time the Constitution was written, there was no prohibition on abortion. It was just accepted that it was something women sometimes had to do. It was a private matter. Not a thought was given to either guaranteeing it as a right or banning it, it was a dirty little fact of life that wasn't talked about. The beginnings of anti-abortion legislation didn't come along until a hundred years later, during the Victorian era.