If something is going to shake up the race before the Iowa caucuses, it’s likely to be a debate. So we partnered with Ipsos to once again track how Thursday’s debate, hosted by ABC News , affected likely primary voters’ feelings about the candidates. The FiveThirtyEight/Ipsos poll, conducted using Ipsos’s KnowledgePanel, interviewed the same group of voters twice to capture both the “before” and “after” picture of the debate.

To better understand which candidates did well or poorly Thursday night, we plotted how favorably respondents rated the candidates before the debate vs. how debate-watchers rated their performance. Warren was one of the better-liked candidates going into the debate, but her performance was still rated higher than we’d expect based on her favorability alone. The same was true of Booker, Buttigieg and (especially) O’Rourke. Interestingly, Klobuchar didn’t get a great debate rating, but it’s not bad considering her pre-debate favorability, which was pretty neutral. Biden and Sanders are very popular with Democrats but failed to get correspondingly high scores on their debate performance, while Castro stands out for getting the worst debate grade — even considering his relatively lukewarm favorability rating going in.

The numbers behind the chart

Candidate Pre-debate favorability Debate performance Elizabeth Warren 70.2% 3.3 Pete Buttigieg 65.7 3.1 Beto O’Rourke 58.9 3.1 Cory Booker 59.8 3.0 Bernie Sanders 66.3 3.0 Joe Biden 67.6 3.0 Kamala Harris 61.8 2.9 Amy Klobuchar 52.8 2.8 Andrew Yang 56.3 2.7 Julián Castro 58.0 2.5

In terms of raw debate grades — respondents graded on a four-point scale (higher scores are better) — Warren, Buttigieg and O’Rourke did best. Booker, Sanders, Biden and Harris did fine.