Bill Clinton was a lucky dog. In 1992, Clinton came to the Wisconsin Capitol on an October day so gorgeous that 30,000 people filled the south lawn. No one minded that he was very late and we had to hear from every local Democrat down to the secretary of the dog catchers union. (Now that we know Bill better, I wonder what he was up to while we waited.) I flashed back to that day Wednesday because at the Clinton rally, I had a baby in a backpack. She was with me again Wednesday, a teenager all too happy to...