Joe Biden opens up biggest national poll lead over Trump since securing nomination as independents abandon president

Joe Biden has opened up his biggest poll lead over Donald Trump since securing the nomination, with a new nationwide survey showing him with a 15-point advantage in the race for the White House.Registered voters back the former vice president over the incumbent 52 - 37 per cent, according to a Quinnipiac University national poll released on Wednesday. The same poll one month ago gave Mr Biden a lead of eight points, 49 - 41 per cent.