OPINION - Tim Walz is everybody's favourite uncle, but also a tried and tested attack dog

Kamala Harris has enjoyed three weeks of astonishing momentum by capturing the “hope” represented by Barack Obama’s presidential campaign while copying the “basement” strategy of Joe Biden. Starting tonight at a rally in Philadelphia, she is embarking on a whistle-stop tour of six swing states designed to fire up enthusiasm for her candidacy, while leaving little opportunity for the face-to-face interviews and media scrutiny that could create gaffes that Donald Trump can exploit.