House Speaker John A. Boehner on Wednesday tapped three top Republicans with spending-cuts credentials to join the 12-member super committee tasked with finding $1.5 trillion in deficit-lowering tax increases or spending cuts.

Mr. Boehner selected Rep. Dave Camp of Michigan, who is Congress’s chief tax-writer; Rep. Fred Upton of Michigan, who is chairman of the Energy and Commerce Committee; and Rep. Jeb Hensarling of Texas, who is chairman of the House Republican Conference.

Already, Republicans signaled they will focus on cutting spending as they try to bring Washington’s record debt and staggering annual deficits under control...