FILE - In this Jan. 24, 2014, file photo, Weld County District Attorney Ken Buck speaks to supporters during a campaign dinner event at Johnson's Corner, a truck stop and diner in Johnstown, Colo. Republican primaries this election year will be a crucial test for the Tea Party movement as the GOP establishment has aggressively challenged tea party-backed candidates in Kentucky, Kansas, Idaho, Mississippi, Michigan and elsewhere. Tea party-affiliated Buck, who lost a close Senate race in 2010, stepped aside to run for the House this week while more mainstream Rep. Cory Gardner launched a Senate bid in a political deal. (AP Photo/Brennan Linsley, File)