Next Tuesday night, Republicans and Democrats hold precinct caucuses to elect delegates to this summer's party conventions. This week, Minnesota Public Radio is profiling the candidates vying for their endorsement for Governor. State Senator Doug Johnson has not formally entered the race yet, but for all practical purposes, he's running. He's set up a campaign fund and he's lining up some of the DFL's savviest strategists to help him make up for his late start. Minnesota Public Radio's Martin Kaste has this profile: Doug Johnson is a consummate insider -- he's served in the Legislature since 1970, and he's held one of the most powerful positions -- Senate Tax Committee chairman -- since 1980. But he's also an Iron Range political insider, which means he's always sure to keep a populist touch: