What you say makes a lot of sense!!!
If a fetus is just tissue, the government has no more place stopping an abortion than they have stopping liposuction. If a fetus is a human, they have no more business allowing abortion than they have allowing me to decapitate my neighbor because his stereo is too loud.
The problem is, the humanity of the fetus is beyond a shadow of a doubt. The only way one can deny it is to fall back on spiritually-based explanations that have no empirical backup (or potential to be falsified) and cannot possibly be used as a basis for law.