This poll was conducted by Sienna College in conjunction with the NYT. 538 rates the pollster as. A+. The poll was conducted January 20 through 23 of 584 Democratic LV and has a margin of error +/-4.8%.
As everyone knows by now Iowa uses the arcane caucus system and in 2020 if your 1st preference reaches "viability", otherwise known as the 15% threshold, you may not vote during the "realignment". Durinng realignment those persons that voted for a candidate that was not viabile may
Correction here
as pointed out below a person may during the realignment join a candidate that was viable during the first round or to another candidate that was not viable in the 1st round or uncommitted.
(only choose to join any one of the candidates that reached viability.) This was an error and should be disregarded but is left to show the error.
1st Choice Results
Narrowed Field Including 2nd Choices
Projected Final Results
Sanders 30%
Biden 23%
Buttigieg 23%
Warren 19%
From the NYT analysis of the poll. Note the NYT article does not have the crosstabs. The link below is to the actual poll.
"The rise of Mr. Sanders has come at the expense of his fellow progressive, Senator Elizabeth Warren: she dropped from 22 percent in the October poll, enough to lead the field, to 15 percent in this survey. Senator Amy Klobuchar, who is garnering 8 percent, is the only other candidate approaching double digits."
"Despite Mr. Sanders’s ascent, the combined strength of the moderate candidates is unmistakable. The poll showed that 55 percent of those surveyed said they preferred a standard-bearer who is “more moderate than most Democrats.” Just 38 percent said they wanted one who is “more liberal than most Democrats.”
"Klobuchar’s supporters could play the most crucial role, though, should she fail to achieve 15 percent in most precincts. When voters were asked whom they would support if they were left with only four choices — Mr. Sanders, Mr. Buttigieg, Mr. Biden and Ms. Warren — Mr. Biden was the overwhelming favorite of Ms. Klobuchar’s backers. He received 55 percent of them in this scenario while Ms. Warren received 18 percent."
Sienna Poll Results
The link takes you to the Sienna College site and then there is a PDF to the crosstabs for the actual poll.
When looking at the crosstabs several things surprised me.
First 40% indicated they could still change their minds and 11% are still undecided so last minute decisions could obviously totally change the outcome.
Sanders has under whelming support from women each candidates support male/female (+/- female support)
Sanders 34/17 (-17)
Biden 14/20 (+6)
Warren 10/19 (+9)
Buttigieg 15/20 (+5)
Klobuchar 9/7 (-2)
This then was also reflected in a policy question of who would improve health care with only 24% of women believing Sanders would while 42% of men believed Sanders would improve health care. The poll didn't ask about M4A so this difference is surprising since it clearly is the issue he is most identified with although he had the highest rating of 32% on this issue.
The split continued on other issues but around a 7 point difference between men and women but was still more stark than other candidates .
24% of the respondents that caucused for Sanders in 2016 (39% of those surveyed) have switched allegiance with 42% of them going to Warren, 28% to Buttigieg and 5% to Biden with Sanders maintaining the balance.
Of course the problem for Warren is that while she leads among 2nd choices it is with candidates most likely to reach viability such as Sanders so they will never have a chance to support her.