Former Vice President Kamala Harris’ attempt to inspire voters at a Democratic rally in Mississippi fell flat Thursday after she was forced to repeat a confusing quote in a far-from-full high school gym. “You know, I mentor a lot of young people, and I talk to them sometimes and part of the advice I give them is, you know, never let someone else with limited ability to see your capacity be a limitation on your ambition,” Harris said at the Columbus, Miss., rally for Democratic Senate hopeful Scott Colom. The applause line received barely any reaction from the crowd, prompting...