Republicans will decide in Wyoming’s primaries whether to stick with a long-serving U.S. senator and first-term congresswoman or change up to political underdogs. Republican Sen. John Barrasso on Tuesday faces a challenge from Casper-area financial advisor Reid Rasner in his pursuit of a third full term. Republican Rep. Harriet Hageman is challenged by Casper attorney Steven Helling, who has switched parties since finishing third in the Democratic U.S. House primary two years ago. Political newcomers are Democrats' only choice for Senate and House. Scott Morrow of Laramie is the lone Democratic candidate for Senate and Kyle Cameron of Cheyenne the only Democratic candidate for House.