Leftist with lofty goals still have to settle - This is the real world, and far from an idealized utopia. We can step into the light while still recognizing we’re walking in the shade. Pro-rehabilitation folks still can believe that not all people can be rehabilitated. Capital punishment may sometimes be the only fitting remedy for civilization, if not just for the punished. There will always be evil in the world who aren’t capable of rehabilitation without some form of violence and punishment - Some crimes and criminals are beyond what the sane and just can fathom.
My former boss’s wife used to steer very strangely when driving - The Jeep was likely out of alignment, but instead of staying centered and making continuous small corrections, she’d let it drift to one side till it was on the line then quickly correct back towards center and then continue drifting, endlessly until arriving at the destination.