on the side of the angels
Supporting the good side, as in Whatever you may think of him, on important issues he's usually on the side of the angels. This expression was coined by Benjamin Disraeli in 1864 in a speech about Darwin's theory that man is descended from apes: "The question is this: Is man an ape or an angel? Now I am on the side of the angels." Before long it was extended to broader use, specifically to the moral view.