Previewing Biden's Philadelphia Speech, Also Sarah Palin's Loss, and Serena Williams' Victory

RealClearPolitics co-founder and president Tom Bevan and Washington bureau chief Carl Cannon look ahead to President Joe Biden's address to the nation tonight in Philadelphia. They also discuss rank choice voting and its role in the defeat of Sarah Palin in a special election for the House of Representatives in Alaska, and congratulate Serena Williams on last night's victory at the US Open Tennis Tournament.