The House committee investigating last year’s U.S. Capitol attack is confronting the question of how to deal with Republican lawmakers who refuse to participate in its probe. Mr. Jordan sent a letter to the committee’s chairman, Democratic Rep. Bennie G. Thompson of Mississippi, saying he would not participate with the “partisan” investigation. In response to Mr. Jordan’s letter, a spokesman for the Jan. 6 select committee accused the lawmaker of backtracking his initial intentions to cooperate with the panel on their investigation.