Harry Enten: “Biden’s lead has been about as stable as they come. Since the beginning of June, he’s been up by around 8 to 10 points. We’ll see whether the convention period, that begins tomorrow, alters the race. For now though, we can say Biden’s doing better than any challenger heading into the major party conventions since scientific polling began. In the 13 previous elections in which an incumbent was running for another term, no challenger has ever been at or above 50% in the polls at this point in the campaign. The closest were Jimmy Carter in 1976 and Thomas Dewey in 1948. Carter was at about 49%, while Dewey came in at between 48% and 49%. Most challengers were not even near that mark. The average opponent to the incumbent comes in at a mere 38% since 1940. Biden is nearly 15 points higher than that at this time. Of course, It’s not just that Biden is scoring a higher percentage of the vote. It’s that he is ahead by a significant margin. Again, the only two challengers who were ahead outside the margin of error at this point were Carter in 1976 and Dewey in 1948.”