US presidential polls: Harris leads Trump nationally, but key swing state races tighter

Race so close in swing states one commentator this week called it the equivalent of a knife fight in a phone booth'

As next week's crucial presidential debate looms into view, Kamala Harris has maintained her narrow lead over Donald Trump in head-to-head polls but is locked in a tighter race in the crucial swing states needed to win the US election.

Ever since Harris entered the contest - after Joe Biden dropped out following a disastrous debate performance that highlighted fears over his age and mental acuity - the vice-president has ridden a wave of support and enthusiasm, turning the race on its head. A solid but slight Trump advantage morphed into a Harris lead.