A former Arizona sheriff revered by the militia movement for his outspoken criticism of gun control and government tyranny is returning to the Inland Northwest for meetings with local GOP groups, triggering a rift among some Republicans. Richard Mack, who now lives in Texas and is running for U.S. Congress, is a self-described conservative constitutionalist with ties to various political parties and movements. He served as sheriff of rural Graham County, Ariz., as a Democrat, ran unsuccessfully for governor of Utah as a Libertarian and now is trying to unseat a Republican member of the U.S. House of Representatives in the GOP’s upcoming Texas primary.