Lauren Boebert and Trisha Calvarese are vying for Colorado's 4th Congressional District seat, formerly held by Republican Ken Buck.

Buck claims his resignation stems solely from his growing frustration with congressional inaction; however, the move is negatively impacting one of his colleagues, Congresswoman Lauren Boebert.

Ken Buck, the representative of the Fourth Congressional District of the State of Colorado to the House of Representatives of the United States Congress, has tendered his resignation from office ...

Republican candidates vying to succeed former U.S. Rep. Ken Buck in the 4th Congressional District will debate tonight. Watch it here: 9NEWS and Colorado Politics are hosting the debate among six ...

Greg Lopez wins nomination for special election, will serve remainder of Buck's term 00:39. After hours of voting, Greg Lopez was chosen as the Republican nominee for the Colorado's Congressional ...