Who was coming to Welch that was famous?
I believe you might be referring to Jack Kennedy. Homer and Emily Sue are in Welch to buy a suit for Homer to wear when he represents his high school at the national science fair. After he buys his suit, Homer goes out to find Emily Sue and he sees that there is a crowd of people gathered holding signs that say "Jack Kennedy for President." There is a presidential election going on at the time of the novel and Kennedy is going through the country on campaign trips. Senator Kennedy is about to make a speech, right there in Welch. Homer listens to the Kennedy speech, noticing that Kennedy seems to be in pain because he keeps touching his back. In fact, this is true. JFK was known to have suffered from back pain all his life. Homer recalls several things he father has told him about Kennedy and the government. When JFK asks for questions, Homer raises his hand and asks him what he is going to do about space if he gets elected. Kennedy replies, "What do YOU think we ought to do in space?"