In response to the recent main page about an anti-abortion amendment, I agree that we can't really propose an amendment we disagree with ourselves. That would reek of political pandering.
On the other hand, we can't propose one to enshrine abortion in the Constitution, because that would imply that up to that point it was not constitutional.
However, we could offer an amendment auxilliary to the discussion of abortion, that the Republicans would have to oppose if they opposed abortion, and that could be widely popular. It's based on the following question:
What is a person?
It never really says in the Constitution. In 1789 it was generally held to mean free males. Women and slaves were not granted all the rights given to "persons" in the constitution. They were given some, but not nearly all.
In today's legalese world, we need to know for sure what a person is. Are women, gays, Negroes, Jews, Muslims, and Asians people? Are fetuses people? Are great apes people? Are corporations people? Are robots people?
Obviously, defining a "person" without referring to "person" is a very difficult task. We don't want to start talking about "46 chromosomes" and "opposible thumbs" in the Constitution, and those wouldn't even apply to some people, such as those with Downs' Syndrome and amputees, respectively.
Such language is clearly not present in the Constitution. It is clearly a progressive and noble goal to ensure that all persons have equal rights, and that these rights not be infringed by creatively giving such rights to non-people. Furthermore, it should not be at the whim of Congress to have this change routinely. Thus, I believe that a Definition of Personhood (better name requested) Amendment would be reasonable to suggest.
I can't quite write legalese, but here's the idea of what I think the amendment should read. The one problem is that it sounds a whole lot like treating "non-persons" as slaves, and doubtlessly that will be the metaphor used to attack any such concept. Any changes to remedy this would be greatly appreciated. Also, if this sounds too much like ERA or not enough like ERA, please mention it and any changes that might need to be made.
Article 1: A person is defined to be any human being that is capable of sustaining life independently from any other specific human being. - This allows for terminally ill patients who require medical care, babies who need parental attention, as well as anyone who buys food from someone else. "Human being" still isn't well defined, but I can't think of anything other than "The children of human beings are human beings". A better definition does need to be included. No right winger will vote for not defining fetuses as people.
Article 2: No laws shall grant a specific group of people special rights over any other group of people. Any rights, contracts, or other interactions between groups of people shall be allowed regardless of what people are involved. - I think that, besides outlawing slavery and the like, this would make gay marriage legal. I doubt this would stay as its exact form, but it will sure get the right riled up.
Article 3: No laws regarding the rights of people shall be construed as to grant those rights to any non-people. - This means that, for instance, an abortion cannot be construed as murder. As all the pro-life arguments depend on this, their case falls apart.
Article 4: Non-people entities still are entitled to protection under the law, and ought to maintain rights as well. However, these rights are not to be conveyed as to impinge on the rights of people. - This makes clear that stuff like "cruelty to animals" laws will still exist. However, by this point it should be perfectly clear that abortion laws will not hold any weight. If it isn't, something needs to be fixed.
Article 5: This amendment shall not have effect if not ratified by 3/4 of the states within 7 years of ratification by the House and Senate. - Always have a time limit.