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 politics reporter Eric Jansen interviewed DFL candidate John Marty, a fourth-term state senator who lost a bid for governor four years ago. John Marty says a key difference between him and most (other) politicians is his refusal to take money from lobbyists and political action committees. He says that's why he can, as he puts it, fight the tough fights, like defeating plans to publicly finance a new ball park for the Mi