The president has intensified his attacks as the midterm elections for control of Congress draw nearer and as the fight over the confirmation of Supreme Court Justice Brett Kavanaugh has grown increasingly fraught. With his ridiculing of a woman who accused Kavanaugh of sexual assault and references to a left-wing "mob," Trump has provided a template for congressional candidates to follow. "My fear is that the Rubicon has been crossed," said Barbara Perry, a presidential historian at UVA’s Miller Center of Public Affairs. "Others will see that this is the way to power and will use this model a...