Hillary Clinton, already seeing an uptick from her strong performance in the first Democratic primary debate, is likely to get another boost following Vice President Joe Biden's announcement on Wednesday that he won't run for president.
Recent polling tells a consistent story: With Biden out of the race, his supporters will disperse -- and that's generally to Clinton's benefit.
In the most recent Economist/YouGov survey, which was conducted earlier this month, one-fifth of Democratic voters named Biden as their preferred candidate. Among that group, 51 percent said Clinton would be their second choice, while just 30 percent named Sanders and the rest were mostly unsure.
Across six October surveys that reported results with and without Biden, Clinton led Sanders by an average of 23 points when Biden was included, and by 29 points when he was not.
With Biden in the mix, Clinton's share of the vote fell as low as 45 percent; without him, she took a majority of the vote in each case. That's substantially higher than she was polling even during her time as the front-runner in the fall of 2007, leading up to the 2008 Democratic primary.
Biden rose in the polls this summer as Clinton suffered from difficult news stories and declining ratings, and as speculation about his candidacy continued to mount.
Even earlier this month, most Democrats didn't think it was too late for the vice president to jump in. But after his absence from the first primary debate, surveys showed, Biden's numbers were already beginning to slide -- and now that he's decided against a run, the largely moderate Democratic voters who were backing Biden look more inclined to rejoin the Clinton camp.
As a summer Economist/YouGov poll showed, Clinton and Biden are perceived as holding virtually identical political ideologies, and Sanders is seen as a more liberal alternative. In the most recent survey, about two-thirds of Biden's supporters considered themselves political moderates or conservatives, similar to the 61 percent of Clinton supporters who assigned themselves the same labels. In contrast, just one-third of Sanders backers say they're not ideologically liberal.
The primary election remains months away, and there's plenty of time for things to change. But Sanders' and Clinton's other rivals continue to face a formidable challenge in opposing a candidate with a solid majority of support. With Biden stepping aside, the path to victory for another Democrat now looks even steeper.
Also on HuffPost: