While Trump cut into Biden’s edge with several demographic groups between the two surveys, some of the president’s biggest gains came among women and the youngest voters, two groups that are typically seen as some of his weakest voting blocs. Trump trails Biden by 11 points among women in the latest poll, conducted Oct. 25-28, compared with a 20-point gap in June.

And while he still lags 14 points behind Biden among voters ages 18 to 29, that’s a significant improvement on the 28-point deficit he faced in June. Independents are also falling in line with the incumbent: Biden’s 1-point lead among those voters is down from an 11-point edge in June.

Biden is not the only Democratic candidate to see his head-to-head advantage over Trump dwindle — and his numbers against the president still compare favorably with his competitors. Sen. Bernie Sanders (I-Vt.) only leads Trump by 2 points in the latest poll, down 8 points since June.

But polling suggests that many primary voters are backing Biden because of his perceived general-election strength. Forty percent of Democratic primary voters said in September that they thought Biden has the best chance of beating Trump in 2020, more than twice the share who said the same of any other candidate. To that extent, declining returns in head-to-head matchups against Trump may pose a unique risk to his prospects for securing the nomination.