We all know the Republican Party has changed in recent years. Tommy Thompson's bid for the U.S. Senate may tell us how much. On Monday, Thompson will incorporate his Senate campaign committee, he said in an interview. That allows him to start raising money, and means a filing of candidacy should follow by early next month. But the real personal and political drama will unfold in the months to come, as the former titan of Wisconsin politics makes his case for a comeback, and deals with questions from conservatives within his own party. "I'm the original conservative," said Thompson on...