The distinction is one of competence or which unit of government - neighborhood, city/county, state, or national is best able to decide and handle such issues.
Some will want to own slaves, or not respect property rights, or have abortions. But none of these have any cause to be a national concern.
Murder is not a federal crime, nor should it be (excepting when treason and piracy are involved, or perhaps other serious things involving the feds as a prime factor).
If I'm standing in Ohio, and you are across in Pennsylvania, and I shoot and kill you, the only question is one of jurisdiction. Murder is and ought to be illegal on both sides of that line.
If some state decides abortion is not immoral, or equally not something they ought to address at the state level, it should be their choice too, just as a state that decides the opposite. There were slave and free states before the secession and war. I don't know if it would have died out (but a Wilberforce didn't arise to find a peaceful way to end it), but ripping thing apart was not good.
Nor was Roe v. Wade which overrode the laws at the time - there were abortion states and life states (I'm not going to try to shift vocabulary to be polite - you know what I mean). Abortion might have died out, or it may have spread, but it would be on a state by state basis, and with restrictions (partial birth or past viability would likely never have been made legal anywhere, 1st trimester maybe more places).
But the right end requires the right means. We don't go around shooting every abortion doctor and destroying the clinics. Nor would it be appropriate to threaten to set off a nuclear bomb if it wasn't banned. Banning it at the Federal level is equally evil to permitting it (there is the case of military and veterans health care though which would apply).
The reason you shouldn't ban abortions at the federal level is at root the same as the reason we shouldn't use terror to stop them - it is the wrong - evil - means.