[Strangler Lewis]

The U.S. Constitution guarantees due process of law to persons. (Persons, it was understood at the time of the 14th amendment would include corporations.) In Roe, the U.S. Supreme Court held that fetuses are not "persons" and therefore have no life or liberty interest that the government should protect (even assuming that abortion could be deemed state action in some respect). Roe has nothing to do with citizenship or who is an American.

Dogs also are not people. Therefore, they are not protected under the due process clause of the fourteenth amendment. This is not to say that states or localities cannot hold their own dog courts before deciding whether or not a dog should be put down.

As far as the "leave it to Congress" view, I'm not at all sure that Congress really has the power under the Constitution to pass laws prohibiting some or all abortions, private homosexual conduct, etc.