"I" am not a clump of cells. I am the ghost in the machine. A pattern, existing in a biological computer, piloting a meat mech. Once that pattern ceases to exist, "I" cease to exist, even if the meat mech is still fully functional. At that point, what remains is just a clump of cells. Or, more usefully, a collection of spare parts, for other meat mechs.

For many, the key difference between a fetus/baby and a "clump of cells" is the ability to support similar patterns (a soul, if you will). Almost all abortions happen long before the clump of cells develops to the point it can support such a pattern. (Neurons alone aren't enough, it needs a critical mass and proper wiring)

There is a potential for argument on late term abortions. I agree that should be restricted. Even that, however need to be dealt with with solomness, logic and care, not emotional knee jerking.