Ivanka Trump had spent much of the day trying to keep her father from going too far. She had refused to address the rally on the Ellipse but at the last minute was so concerned by her father’s anger toward Mr. Pence that she decided to accompany him there in hopes of avoiding a worse clash. Over the following hours, as rioters rampaged through the Capitol, she ran up and down the stairs in the West Wing from her office to the Oval Office hoping to persuade her father to issue stronger statements calling off the attackers.