Good, if it made you feel better, and hopefully helped to clarify your own personal boundaries. Because right now, clarifying those boundaries is essential, especially when your kids are in danger. But do we need to tell people our boundaries? Or simply live them instead? Which would hold more power in your situation?
And do know it doesn't matter what you say or don't say right now. He isn't hearing you. His alcoholic voice overshadows everything, including his good judgment and reason. Yes, it is that powerful. And yes, he already knows driving the kids around when he is drunk is not OK. Can't be a grown up in this country and not know this. He knows. He just can't stop himself once he's put that first drink in his mouth.