How do I think on my feet when a judge pushes back?

You can argue a prepared motion well now. What still rattles you is the live moment when the judge pushes back and the script is gone. That is the hardest part of advocacy, and being thrown by it does not mean you lack the skill. It means you are meeting the part that only live reps can teach. When the judge pushes, your job is not to have the perfect answer instantly. It is to stay steady long enough to think. A short pause reads as confidence, not weakness. The silence that feels like forever to you is a breath to everyone else. Before your next appearance, have a few phrases ready to buy time, such as asking to address the point directly. Then breathe once and answer. Practicing the pause, not just the argument, is how thinking on your feet slowly becomes something you trust.