I don't think you can automatically make the equation left = anti, right = pro.
Lenin pleaded with his comrades to keep the death penalty, feeling that it was an essential for the state, having opposed the Tsarist use of it.
Revolutionary movements like the IRA used physical punishments up to and including killing to punish informants.
I would never trust the state as it is presently constituted to execute people, but I do think that the mainstream 'anti' argument has some flaws. -- Jim heartfield