David Paleologos

Suffolk Political Research Center

Correction: A prior version of this article misstated the percentages of support for Joe Biden and Elizabeth Warren. The former vice president’s is 18% and the senator’s is 17%.

You can never underestimate the value of a political debate. Just ask South Bend, Indiana, Mayor Pete Buttigieg, who recently passed Vermont Sen. Bernie Sanders on his way to third place in the 2020 Iowa Democratic caucuses. Buttigieg has vaulted himself into the top tier of candidates on the back of a convincing debate performance, according to today’s Suffolk University/USA TODAY poll of 500 likely Democratic caucusgoers.

Here’s where the race stands in Iowa: Former Vice President Joe Biden (18%) leads Massachusetts Sen. Elizabeth Warren (17%), with Buttigieg capturing 13%, Sanders receiving 9%, and billionaire Tom Steyer, Minnesota Sen. Amy Klobuchar, Hawaii Rep. Tulsi Gabbard, and California Sen. Kamala Harris all tied at 3%. A considerable 29% of likely Democratic caucusgoers remain undecided.

The difference between Suffolk/USA TODAY’s summer and fall Iowa polls is more than seasonal: It is a dramatic turnaround for 37-year-old Buttigieg, who more than doubled his second-tier 6% summer standing.

Even more impressive for Buttigieg is how those who watched the CNN/New York Times debate last week would align their support if the caucuses were held today. Among only debate watchers, Buttigieg topped the entire Iowa field with 19%, followed by Biden and Warren (tied at 17%), Sanders (9%), and Klobuchar (6%). Both Buttigieg (39%) and Klobuchar (28%) were seen as debate winners last week.

Buttigieg appears to be getting some traction in his age category when compared to the septuagenarians in the top tier. In the poll, Buttigieg (16%) led Warren (15%), Biden (13%), and Sanders (8%) among Iowans ages 36-55 years.

If the economy becomes a central issue in the presidential race, the Suffolk/USA TODAY poll reveals that Buttigieg may also have an edge. Among Democratic caucusgoers who said the economy is the most important issue affecting their support, Buttigieg topped the field yet again with 20%, followed by Biden and Warren, tied at 11%.

The difference between our last Iowa poll in late June and today’s poll shows the pure impact that a political debate has on candidate viability, aside from daily press releases, clarifications, and policy positions. Back in the summer, Harris had vaulted into the number two spot in Iowa. She was second only to Biden, after engaging him directly in the highly watched first Democratic debates, which took place right before Suffolk fielded that poll.

In the two weeks following the debate, Harris held firmly in second place behind Biden in most of the other public polling. But the Harris campaign, perhaps because of the mid-July timing or a lack of preparation, failed to maximize her meteoric rise in the polls and keep their candidate in the top tier.

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The Suffolk/USA TODAY poll suggests that there may be a bit of debate fatigue in the works: In June, 64% of likely caucusgoers said that they watched at least one of the two debate nights. For the most recent debate, viewership dropped by about half, with only 37% of poll respondents tuning in, even though all 12 candidates shared one stage in one night. One wonders where Buttigieg would stand in the Iowa caucuses today if the debate viewership had been at the June level.

Buttigieg may follow in the footsteps of Harris’ summer swoon, but his campaign is now touting that he has more campaign offices in the state of Iowa than any other Democratic hopeful. It’s hard to say whether Buttigieg’s recent upward move in our poll is due more to his debate performance or his newly formed widespread field presence in Iowa.

In the meantime, Buttigieg is one of the two top second choices among all the candidates. Both Warren (22%) and Buttigieg (14%) led in this important category. It is a key metric in Iowa, where caucusgoers whose candidate’s support is below 15% at their caucus location must choose another candidate.

The big wildcard is how (and how many) independents (“no party”) will end up caucusing as Democrats, once they’ve changed party registration prior to the caucus. With no competitive Republican caucus, independents in Iowa may wish to be counted in the Democratic caucus. In the poll, Buttigieg was tied with Biden (13%), with Warren (7%) and Sanders (5%) trailing. A whopping 40% of independents were undecided, despite declaring their intention to participate in the Democratic caucus in the poll.

Debates, age, the economy, viability, field presence, and second choice votes. So many wildcards left to play out in the Hawkeye state, and so little time.

David Paleologos is director of the Suffolk University Political Research Center.