A Constitutional federal republic is incompatible with a single-issue voter, because a multitude of differing single issue voters will never agree.
For them, the only solution is a benevolent dictator who outlaws abortion by decree.
Well now, don't get me wrong. I'd love to see abortion outlawed completely, though I am sensible enough to realise that this will probably never happen, at least in my lifetime.
If we repealed Roe v. Wade, that would be a good start. Throw it back to the states, and I can see half of them outlawing it, or making it so blithering difficult to obtain that it would be almost non-existent. That would save hundreds of thousands of lives a year, right there - the federalism way.