It's no secret that incumbency gives politicians certain advantages that many of their challengers can't match. Sometimes it's simply a higher public profile. But where to draw the line on using the advantages of office has become an issue in the Minnesota gubernatorial race, which includes two state officeholders - Gov. Tim Pawlenty and Attorney General Mike Hatch. The Republican Party today (Weds) asked for an investigation into Hatch's use of state letterhead on campaign materials, as well as his campaign's use of reports produced by the attorney general's office. Hatch says Republicans are trying to cover up Governor Tim Pawlenty's attempts to use his office for political gain. Minnesota Public Radio's Tom Scheck reports....