DENVER – Tea party favorite Ken Buck has defeated former Lt. Gov. Jane Norton to clinch Colorado's Republican nomination for the U.S. Senate. The vote Tuesday was seen as another blow to politicians with close connections to Washington. Norton was endorsed by GOP leadership and co-chaired John McCain's presidential campaign two years ago in Colorado. Buck, a Weld County prosecutor, was little known before he began courting tea party groups more than a year ago. He trailed Norton in fundraising but used his law enforcement credentials in vowing to crack down on "criminals" at home and in Washington.