Looking more broadly, the other candidates don’t seem to be reaching Biden’s levels against Trump even as they become better known as the year carries on. Sanders has held an average 5-point lead this year in the national polls, which is near his 6-point August edge. Warren’s lead against Trump in the average national poll this year has been 2 points, similar to her 3-point August lead. Harris’ edge has been 1 point in the average poll this year, which is nearly identical to her 2-point August advantage.
And despite leaving the sidelines and reentering the political fray (often a bad thing for one’s popularity), Biden’s numbers are as good against Trump as they have been all year. Biden’s current 10-point advantage over Trump is better than his average 8-point advantage this year and 8-point advantage in the polls taken this year before he declared his candidacy.
Biden’s numbers are holding up significantly better than Hillary Clinton’s did four years ago. Like Biden, Clinton was a former member of Barack Obama’s administration who decided to come out of civilian life to run for president. And like Biden, Clinton declared her candidacy in the April before the primary season.