AMES, Iowa – The top tier of Democratic presidential candidates remains relatively unchanged in the latest Iowa State University/Civiqs poll.

Mayor Pete Buttigieg continues to lead the pack at 24%, followed by Sen. Bernie Sanders at 21% who jumped ahead of Sen. Elizabeth Warren at 18%. Joe Biden remains in fourth with 15% of likely Iowa caucus-goers selecting the former vice president as their top choice. Dave Peterson, a professor and Whitaker Lindgren faculty fellow in political science who organizes the poll, says Iowa Democrats appear to be narrowing the field of candidates they’re considering.

“We asked Iowans to list their first choice, second choice, and who they are considering. Less than 40% of Iowa Democrats even listed a single candidate who they were considering after their second choice,” Peterson said. “In contrast, the number of Democrats who listed at least one candidate they did not want increased to just shy of 70%.”

The online poll of 632 likely Democratic caucus-goers was conducted Dec. 12-16. A majority of survey respondents have been interviewed each month to understand how voter preferences are changing leading up to the Iowa caucuses on Feb. 3. Peterson says while Warren and Sanders flipped spots from last month’s poll, none of the candidates in the top tier moved more than 3%.

No breakthroughs in the second tier

The second tier candidates show no signs of a breakthrough, Peterson said. Sen. Amy Klobuchar, who is in fifth, is down slightly from last month with 4%. And Peterson says there is growing opposition to candidates at the bottom of the second tier.

“For seven of the bottom eight candidates, more Iowans say they do not want them as the nominee than Iowans who say they are even considering them. It is particularly bad for Bloomberg and Steyer,” Peterson said. “Iowa Democrats have been unwelcoming to Bloomberg ever since he announced his candidacy, but the negative opinions of Steyer have increased. Many of the respondents seem to think of them as a pair, indicating opposition to the billionaires in the race.”

The online survey was sent to selected members of the Civiqs research panel. Likely caucus attendees were identified as those who responded they would “definitely” or “probably” attend the Iowa Democratic Caucuses and identified as Democrats or independents. An oversample of Democrats and independents were selected to produce a larger number of likely caucus attendees.

Demographic data were collected in previous Civiqs surveys. The results for registered voters are weighted by age, race, gender, education, party and congressional district to be representative of registered voters in Iowa. The survey has a margin of error of plus or minus 4.9%. Results of the next poll are expected in late January.

The Iowa State University/Civiqs poll is funded by Iowa State’s Department of Political Science, Catt Center for Women and Politics, College of Liberal Arts and Sciences, Office of the Vice President for Research and the Whitaker-Lindgren Faculty Fellowship.