Hosted by Jane Pauley. In our cover story, former Congresswoman Liz Cheney explains to John Dickerson why she believes reelecting Donald Trump would mean the end of our republic. Also: Susan Spencer examines efforts to fight the stigma against mental health struggles and suicide; Tracy Smith sits down with Taraji P. Henson, star of the new movie musical "The Color Purple"; Seth Doane looks at a new TV series about movie legend Cary Grant; Jim Axelrod talks with Geddy Lee and Alex Lifeson of the Canadian rock band Rush; Conor Knighton takes a ride on the Alaska Railroad, now marking its 100th year; and Lucy Craft visits a restaurant in Japan where the staff is purposefully, comically rude.