I am not sure that Jesus was anti-death penalty, quite the contrary, did he not say that the 'Tares' (weeds, metaphorical, lost souls, ) should be put in a fire. Though that does contradict the Christian idea of Hell, since a fire of dry weeds does by its nature, burn quickly and only once, not for eternity.
Yes, Hell is an ethnic cleansing fantasy, so anybody who has it as a plank in their platform is an enemy of human rights and decency.