Kamala Harris has all but erased Donald Trump’s polling lead in America’s six swing states, which is testament to the excitement generated by her late entrance into the presidential race. On August 6th she will speak at a rally in Pennsylvania, the most crucial of the swing states, alongside her new running-mate, who may well be Josh Shapiro, the state’s governor. Judging by her past speeches, she will warn that Mr Trump wants to ban abortion, is a threat to democracy and only cares about the rich. Underlying it all will be another message—that the American economy is the world’s strongest, and that the country remains a place of opportunity.