Kamala Harris introduces “coach” Tim Walz, her trusted friend

ACREATE EVERYTHING about the scene in a packed 10,000-seat basketball arena in Philadelphia on the evening of August 6 would have been unimaginable just six weeks ago. First, there was the size and Swiftie-like zeal of a Democratic crowd waving their glow-in-the-dark bracelets, dancing on a DJhis songs and were fired up by the belief that their ticket could actually win the White House in November. Then there were the star attractions on stage: Kamala Harris, officially endorsed as the party’s presidential nominee in an online overnight delegate vote, just over two weeks after Joe Biden’s decision to withdraw. With her was Tim Walz, the governor of the state of Minnesota, Ms. Harris’s newly announced vice-presidential running mate. Not since 1968 has one of America’s two major parties switched a presidential candidate so late in a campaign. Based on current evidence of the effects of movement, they might consider doing this more often.