Recent polls have found more people recognize former State Auditor Mark Dayton than any of the other DFL U.S.Senate candidates. Dayton is a politician who's run in 5 statewide elections, but perhaps more importantly, his name calls to mind the department store his family founded. He came in fourth in the DFL gubernatorial primary two years ago, but this time, many observers think he's got a good shot at winning the Senate primary. In the first of our series of candidate profiles, Minnesota Public Radio's Laura McCallum looks at Mark Dayton's career and campaign...