There is a lengthy book on that subject, Why Are Jews Liberals? by Norman Podhoretz. Norman Podhoretz, definitely not a liberal since the mid-1960's (and I would argue not before then either) reviewed the history of Judaism from its beginnings through modern times, and hints that it has Biblical roots. The roots of handicap protection (the injunction against placing stumbling blocks in the way of the blind), consumer protection (honest weights and measures), labor protection (do not hold the wages...