Why won't my husband just back down and let me give my side of the story?

If you are not on the same page with discipline, your kids will quickly discover that you are not a parenting team. Children need their parents to be on the same page, and since you are repulsed by the thought of spanking your children (and your instincts are right on - spanking is counterproductive and has implications for your children's social development) - he will have to back down so that you can be a team. If you are repulsed by the form of discipline, you will ignore bad behavior rather than confronting it - that is human nature and you will be unable to overcome it. It will lead to inconsistency which is actually THE biggest no no in parenting. Your children will be very confused and suffer if one of you spanks and the other does not, or if you are not consistent in how you discipline. By agreeing to this in any way - you are ACTUALLY undermining YOURSELF.