Joe Biden’s poll lead may be sturdier than Hillary Clinton’s

Joe Biden’s lead in key states is less than Hillary Clinton’s four years ago, despite commanding national edge over Donald Trump.

Hillary Clinton’s virtual address to the Democratic National Convention last week. Picture: AFP

Joe Biden’s lead in key states is less than Hillary Clinton’s was four years ago, despite a commanding national margin over Donald Trump.

In the RealClearPolitics average of polls, Mr Biden leads by 7.1 percentage points — narrower than the 9.3-point lead of a month ago but still enough for Democrats to be cautiously confident. At this stage in 2016 the same average of polls gave Mrs Clinton a lead of six points.

However, in key swing states the margin is slimmer. Pennsylvania, Wisconsin and Michigan – which stunned Democrats by voting Republican for the first time since, respectively, 1988, 1984 and 1988 — are closer at this stage than in 2016.

Joe Biden takes a selfie with supporter Margarita Rebollal after speaking at a Nevada Caucus watch party in February. Picture: AFP

Pennsylvania gives Mr Biden a lead of 5.8 points; on this day in 2016 it gave Mrs Clinton a 9.2-point lead. In Michigan, Mr Biden has a seven-point lead, compared with Mrs Clinton’s lead of nine points. In Wisconsin Mr Biden has a 3.5-point lead; Mrs Clinton’s was 11.5 points on this day.

Only Florida, which Mr Trump claimed back for the Republicans after Barack Obama won it twice, presents a rosier picture, giving Mr Biden a lead of 3.7 points compared with Mrs Clinton’s 2.9 points.

Still, there are reasons to be cautious about this analysis. While campaigners, and pollsters, are obsessing over this quartet of states, in 2016 all of them bar Florida were generally considered impregnably Democratic and so there was far less polling of them, giving an outdated picture.

Moreover, any polls were conducted just after the Democratic convention, which gave Mrs Clinton a bounce of about four points nationally. There is no evidence of a bounce for Mr Biden.

That may show that his convention failed to win over new voters, or it may reflect another difference between this race and that of 2016: its stability.

Between the start of June 2016 and the end of August that year, Mrs Clinton’s margin in the average of polls fluctuated between a lead of six points and a lead of 1.1 for Mr Trump. Mr Biden’s lead since May has stuck between tighter bounds: at its peak a lead of 9.8 points; at its trough a lead of 6.4 points. The polls also show far fewer undecided voters than in 2016, meaning a much smaller group for the President to win over, or for Mr Biden to lose.

Finally, many pollsters concluded after Mr Trump’s 2016 victory that they had surveyed too few voters without degrees. Now most samples reflect the educational diversity.

All this means Mr Biden’s ostensibly narrower leads in swing states may prove to be more durable than Mrs Clinton’s.