So Clinton's position on the death penalty is kind of bizarre for a professional politician, reading the answer on Vox. Basically, she wants to have it for, like, really bad people, like terrorists, but that's it.
This is probably not that uncommon a position among Americans -- on a feelings level, it kind of feels reasonable. The problem is that it's kind of a dumb position! Aside from the potential constitutional issue with having a special punishment we keep in reserve for unusual criminals, I feel like in the end this system just boils down to "rely on the prosecutor, the judge, and the jury to select the specific people who do deserve the death penalty." Which is the system we have now, and we hate it.
I would kind of expect Clinton to have a more coherent response on this issue, especially since Democrats generally don't support the death penalty any more. So a little surprising to me. I guess it doesn't come up much.