Liz Cheney urges investigation of Trump’s ‘every phone call’ on Jan. 6, and Kinzinger makes an emotional appeal for truth.

Representative Liz Cheney, Republican of Wyoming, issued a defiant challenge to her own party on Tuesday as a special House committee began its inquiry into the Jan. 6 attack on the Capitol, saying that the riot would remain a “cancer on our constitutional republic” if Congress failed to hold accountable those who were responsible.

In stern opening remarks, Ms. Cheney, one of just two House Republicans willing to serve on the panel, dared her colleagues to support a full investigation into the worst attack on Congress in centuries.

“Will we be so blinded by partisanship that we throw away the miracle of America?” Ms. Cheney asked. “Do we hate our political adversaries more than we love our country and revere our Constitution?”

Her remarks underscored just how isolated she has become in her own party as one of the few Republicans willing to speak out against President Donald J. Trump and his role in inspiring the attack on the Capitol. Ms. Cheney, the daughter of a powerful conservative family, has already been ousted from Republican leadership for her insistence on calling out the former president and his election lies, and her participation in the inquiry has drawn scorn from party leaders.