FBI furore helps Trump reclaim lead from Clinton in one TV poll
Donald Trump has overtaken Hillary Clinton to take a single percentage point lead in a poll by ABC, the first time he has done so since May.
Though the result remains within ABC's margin of error, the broadcaster said the leaders changing places was a noteworthy moment with just a week to go until election day.
ABC has had the two candidates virtually neck-and-neck for the past week, with aggregated results suggesting Mrs Clinton was ahead by just 0.4 of a percentage point.
But enthusiasm for the Democrat candidate has slumped after the FBI revealed it would be opening up a new investigation into a set of emails sent during Ms Clinton's time as Secretary of State.
It makes the election too close to call, based on ABC's poll alone. Among the other runners, Gary Johnson dropped to a new low of 3% and Green candidate Jill Stein polled at 2%.
The network, which surveyed across the country, has not had Mr Trump in the lead since he was 2% ahead in a hypothetical run-off against Ms Clinton back on May 23 this year.
Then, Mr Trump had just secured the GOP nomination, while Ms Clinton was still engaged in a fight for her place with Bernie Sanders.
Most polls also showed a spike in support for Mr Trump in late July, though ABC was not among those who had the Republican taking an outright lead.
It should also be noted that even this close to an election, a poll on voter preferences is not necessarily indicative of the final result.
ABC noted that Mitt Romney was one point ahead of Barack Obama in a comparable tracking poll in 2012, while John Kerry held an identical advantage over George Bush a week out in 2004.
Earlier Trump took aim at "Obamacare" as well as homing in on the FBI's renewed examination of rival Mrs Clinton's emails as the US election campaign enters its final week.
Campaigning in Pennsylvania, a state where some healthcare premiums are expected to go up by more than 40%, Republican candidate Mr Trump presented an alternate healthcare proposal at a joint appearance with running mate Mike Pence.
Striking a subdued tone and barely mentioning Mrs Clinton's name, the typically fiery Republican still warned that electing his Democratic rival would "destroy American healthcare for ever".
He said: "Obamacare has led to higher prices, fewer choices and lower quality. Hillary Clinton wants to expand Obamacare and make it even more expensive." As Mrs Clinton's national lead shrinks, she is relying on a firewall of support from women and minority voters in demographically diverse swing states.
With more than 23 million ballots already cast through early voting, Mr Trump simply may not have the time or organisational capacity to improve his standing enough over the next week to enter the White House.
The Democratic presidential nominee and her allies in a dozen battleground states have more than 4,800 people knocking on doors, making phone calls and otherwise working to support her candidacy.