Yeah, I've been looking that up.
Harry Thomas Jr. voted "yes," is black, and his ward (5) is the second-poorest Ward after Ward 8 -- I can't find any racial demographics (just economic) but from references to it, it seems to also be a majority-black ward. Haven't found anything about Thomas' constituents being mad at him, though of course it's possible that I'm just not finding it, rather than that they're not mad at him.
That's all kind of an aside, though, not a direct claim--> refute sort of thing. Your post reminded me of Coates' point, which I thought was a good one.
Anyway... we've gotten away from "right reasons" and towards "smart reasons." I still think that there isn't some blanket rightness about politicians voting for what (they think that) the majority of their constituents want, no matter what the issue may be.
If we must hold both the euthanasia guy and Barry to the same narrow standard -- and I'd prefer something less rigid, especially something that takes into account the end result -- I'd come down on the side of saying that if the euthanasia guy (sorry I forgot his name) really strongly personally opposed euthanasia, he either shouldn't have signed it or else should have recused himself. Not that Barry did the right thing by going against his own long-standing beliefs and actions in an attempt to stay in power.