The past few weeks have been pretty good for South Bend, Indiana, Mayor Pete Buttigieg: His polls are on the upswing in Iowa, he’s getting more media coverage, and he even led in a New Hampshire poll. It seems that he carried this momentum through the fifth Democratic debate as well. According to our FiveThirtyEight/Ipsos poll conducted using Ipsos’s KnowledgePanel, he saw the largest increase in the number of people considering supporting him, going from 26 percent before the debate to 32 percent afterward.

But where did that 6-point increase come from?

To answer this, we looked at a few metrics in our poll, which surveyed the same group of respondents before and after the November debate. One of the indicators we considered is how support shifted among respondents who prioritized the top five issues in our poll, which were health care, the economy and jobs, wealth and income inequality, climate change, and discrimination. As you can see in the table below, Buttigieg gained potential supporters among voters who prioritized all of the top 5 issue areas — he is the only candidate for which this was true. His gains were not marginal either, mostly around 5 percentage points.

Buttigieg gained among voters who prioritize … Change in the share of respondents considering supporting each candidate before and after the fifth Democratic debate by which issue respondents said was most important to them, per a FiveThirtyEight/Ipsos poll candidate Health care The economy and jobs Wealth and income inequality Climate change Racism, sexism, discrimination Biden +1.9 +0.8 +2.4 -2.6 +3.0 Sanders +1.3 -2.9 +3.1 +0.5 +0.6 Warren +0.5 -2.3 +0.3 +2.5 -5.7 Buttigieg +5.0 +4.8 +5.7 +6.3 +3.7 Harris +5.3 +2.2 +2.2 +6.2 -3.0 Yang +1.7 +0.0 +0.8 +1.3 -0.2 Booker +3.7 +1.8 +1.6 +3.5 -0.4 Klobuchar +0.8 +1.3 +1.2 +3.1 -1.1 Gabbard +0.1 +0.6 +0.7 +0.4 +0.5 Steyer +3.8 +1.3 +0.7 +1.2 -0.3 Showing the top five issues out of a set of twelve respondents could choose from. Uses respondents’ pre-debate answer for which issue is most important. From a survey of 3,786 likely Democratic primary voters who were surveyed between Nov. 14 and Nov. 18. The same people were surveyed again from Nov. 20 to Nov. 21; 2,077 responded to the second wave.

When respondents were asked to rate candidates’ chances of beating President Trump, Buttigieg gained ground there as well, earning a post-debate average of 49.5 percent, 3 points higher than his pre-debate average. He still trails former Vice President Joe Biden (67.5 percent after the debate), Sen. Bernie Sanders (58.5 percent) and Sen. Elizabeth Warren (57.8 percent), but notably, he was the only one of these four candidates who gained in this metric — the other three either lost ground or saw no change.

But if Buttigieg was hoping his high debate marks would help him diversify his base of support, that hasn’t happened yet. The demographic cross-tabs in our poll show that he mainly made inroads among groups where he already enjoyed a disproportionate amount of support, like the college-educated, white voters and older voters. He had little success winning people over among groups where he has tended to struggle, like with black and Hispanic voters.

Buttigieg’s gains were mostly confined to his base Share of respondents considering supporting Buttigieg in a FiveThirtyEight/Ipsos poll, broken down by demographics Age pre-debate post-debate change 65+ 36.6% 44.5% +7.9 50-64 30.1 37.8 +7.7 18-34 19.7 24.4 +4.7 35-49 22.0 24.5 +2.4 education pre-debate post-debate change College or higher 34.2% 41.6% +7.4 Some college 23.9 28.4 +4.5 High school or less 17.9 22.0 +4.1 race pre-debate post-debate change White 34.5% 42.4% +7.8 Black 12.2 15.9 +3.7 Hispanic 17.4 16.3 -1.1 Only groups with a sample size of 200 or more were included. From a survey of 3,786 likely Democratic primary voters who were surveyed between Nov. 14 and Nov. 18. The same people were surveyed again from Nov. 20 to Nov. 21; 2,077 responded to the second wave.

This lack of diverse support may be a part of why Buttigieg is struggling to gain traction outside Iowa and New Hampshire and continues to sit at about 8 percent nationally, far behind the other three front-runners in the race. And if Buttigieg can’t appeal to people outside his existing base, he might have a hard time getting his numbers up any higher.





FiveThirtyEight Politics Podcast: Has public opinion shifted on impeachment?