Photo Illustration by Thomas Levinson/The Daily Beast/Getty/TimForMt.comOne of the GOP’s best hopes to reclaim control of the U.S. Senate, Montana candidate Tim Sheehy, has made cleaning up the much-maligned “Washington swamp” a core promise of his campaign.As he ramps up his bid in one of the most critical states for determining the Senate majority, Sheehy has built a case against Sen. Jon Tester that centers on the incumbent Democrat’s alleged coziness with lobbyists, after Tester failed to he