Where in the Constitution does it state that the Federal Government has the right to usurp the State outside of the 10'th Amendments limitations? You see, that's the slippery slope. Use big federal government to stop one thing we don't like (abortion), but cry foul when the left uses it to usurp a state's decision on something they don't like. Big government is all bad for everybody. It's most certainly a state's decision. In fact, if you look at the founders' intent, and until the 14'th Amendment was enacted (never truly ratified) after the civil war, the Constitution was an agreement between the states and then the individual states' constitutions were between the states and the people. The Bill of Rights (and the Constitution as a whole) was an agreement between the states that none would use the confederacy to restrict those rights amongst the people of each others states. However, the Bill of Rights NEVER was intended to place bans on the people of the states; the Bill of Rights and the Constitution was to place bans on the confederacy (or, now the "Federal Government") as a treaty of sorts. Therefore, the federal government has no right - nor should it - to allow or disallow abortion, it's completely a state by state issue. In fact, if it had been left to the states as Constitutionally mandated, we would have saved millions upon millions of innocent babies by now. But since the left used the federal government to usurp state's rights (as you now propose), state's were left unconstitutionally helpless to stop the slaughter.
The Fifth and Fourteenth Amendments make it absolutely clear that the states CANNOT make ANY LAWS that deprive a person of life without due process.
Do you believe that an individual state should be allowed to pass a law legalizing murder?