You're obviously more of a Constitutional scholar than I. Personally, I believe that it is an issue that should be left entirely to the states, but I'm not sure the electorate sees it that way. I never underestimate the ignorance of the average voter. They don't understand liberal justices from conservative. Most can't even name a single justice, let alone which is conservative.
I think they see things like partial birth and Kelo as happening on Bush's and the Republican Congress' watch and therefore the GOP is to blame. Add to that the MSM penchant for failing to explain the complexities and various positions of such issues (I don't underestimate the ignorance of the MSM either) and we're left with voters who base their decisions on gut instinct rather than facts.
Hannity's Man On The Street is a prime example. If the average American doesn't know who Cheney, Roberts, Pelosi, and Hastert are, how can you expect them to understand what is and is not the role of the federal government vis-a-vis the US Constitution, State Constitutions, and the SCOTUS?
As my aunt in Florida said, she voted for Nelson because he "looked more honest" than Harris.
Actually, I try not to underestimate their mendacity.