Harris’s popular-vote edge is almost entirely negated by the bigger Electoral College bias against her. In our polls-only forecast pairing Biden against Trump, the Democratic candidate needs to win the popular vote by just 1.1 points to win the presidency. That’s thanks to Biden doing better in Pennsylvania, the likeliest tipping-point state in our model. Harris, by contrast, would need to win the popular vote by 3.5-4 points to win Pennsylvania and, with it, the Electoral College.

In our full forecast model — which includes a variety of non-polling economic and political variables, which we call the “fundamentals” — Harris does much worse than Biden across the board. Whereas Biden has a 48-in-100 chance to win the Electoral College, Harris has only a 31-in-100 chance.

This is thanks in large part to the boost our model confers on Biden as the incumbent president, which is worth an extra point for Biden over Harris in our fundamentals-only forecast of the national popular vote. However, one factor our model does not consider is whether presidents’ approval rating and economic growth impact incumbents running for reelection more than non-incumbents running from the same party, and that may actually push Harris’s numbers over Biden’s. In other words, your mileage may vary depending on how much you believe that Biden should get a boost because he’s the sitting president.