Sen. Elizabeth Warren has taken the lead in a major new Iowa poll, registering slightly ahead of persistent frontrunner Joe Biden in a survey of the state’s Democratic voters. The results come after months of upward momentum by Warren, but it remains to be seen whether she will be able to maintain or build on these numbers: Many respondents indicated that their current picks aren’t set in stone, leaving room for reversals of fortune in the five months leading up to next year’s first caucus.

The latest Des Moines Register/CNN/Mediacom Iowa Poll, released Saturday night, puts Warren’s support among registered Democrats in Iowa at 22 percent, just ahead of Biden’s 20 percent. (The poll has a margin of error of 4 percent).

Warren is also the second choice, or a candidate under active consideration, for more voters than Biden; a tally of those who have the senator as their first or second choice or who are otherwise “actively” considering her is at 71 percent. Biden comes closest to Warren on this metric: 60 percent of voters are considering him in some way.

“This is the first major shake-up,” longtime pollster J. Ann Selzer, president of Selzer & Co., which conducted the poll, told the Des Moines Register. “It’s the first time we’ve had someone other than Joe Biden at the top of the leader board.”

Sen. Bernie Sanders was the only other candidate to reach double-digit support, at 11 percent. Mayor Pete Buttigieg and Sen. Kamala Harris followed, with 9 and 6 percent support respectively.

Elizabeth Warren narrowly leads the @DMRegister/@CNN Iowa Poll for the first time.



Warren: 22%

Biden: 20%

Sanders: 11%

Buttigieg: 9%

Harris: 6%

Booker: 3%

Klobuchar: 3%

Gabbard: 2%

O’Rourke: 2%

Steyer: 2%

Yang: 2%https://t.co/E9WnqJWaT4 — Brianne Pfannenstiel (@brianneDMR) September 22, 2019

Shoring up the above-1 percent club were Sens. Cory Booker of New Jersey and Amy Klobuchar of Minnesota (3 percent); former Rep. Beto O’Rourke of Texas, Rep. Tulsi Gabbard of Hawaii, and entrepreneurs Tom Steyer and Andrew Yang (2 percent).

New York Mayor Bill de Blasio, who ended his campaign on Friday, was not named by a single voter as either a first or second choice for president. Rep. Tim Ryan of Ohio and former Rep. Joe Sestak of Pennsylvania shared in that dubious distinction.

While Warren is now on top, her support remains fluid

As Vox’s Andrew Prokop has explained, the release of Selzer’s poll was eagerly awaited given that her work is considered the “gold standard” of Iowa polling, and because the few recent polls released in that state have come from newer, less-established groups. However, the newest numbers do in fact mirror those of one of the two polls conducted following September’s Democratic primary debate: An online poll by Civiqs conducted for Iowa State University showed Warren in the lead there with 24 percent support, substantially ahead of the tied-for-second Biden and Sanders with 16 percent each.

While the lead suggests the race may be changing, it is important to remember Iowa’s caucuses are five months away. In that time, much can and likely will change. In fact, few Iowa voters — only one in five — told Selzer’s pollsters that they actually have their minds made up. And 63 percent of those polled said they could still change their minds.

Those numbers are even shakier for Warren specifically: Only 12 percent of her supporters say their choice is firm while 88 percent say they could still be convinced to place their support elsewhere. By contrast, a quarter of Biden’s supporters are firm in their choice, with 70 percent saying they could be persuaded to pick another candidate.

“My sense is there’s still opportunity aplenty,” Selzer told the Des Moines Register. “The leaders aren’t all that strong. The universe is not locked in.”

While Warren’s “universe of support” is larger than other candidates, others who fared poorly in this poll could take heart from the numbers reflecting their potential supporters. For example, former HUD secretary Julián Castro, who polled at just 1 percent, has 22 percent of voters considering him.

Castro’s potential support pool still lags well behind other candidates, however, particularly Biden, who still enjoys the second-largest universe of support, at 60 percent. Harris and Buttigieg are tied (55 percent); they are trailed by Sanders (50 percent), followed by Booker (42 percent), O’Rourke (38 percent), and Klobuchar (37 percent).

The good news for Warren is reflective of her steady ascent in the Iowa polls. In Selzer’s polling last December, she registered at 8 percent; she hit 9 percent in March. By June, she became neck-and-neck with Sanders, her fellow progressive, at 15 percent. This is her first time besting the entire field.

For his part, Sanders’s base of support has stagnated in recent months, and this poll represents a small decline. In December, his support was at 19 percent. It increased to 25 percent in March. By June, it had dropped back to 16 percent.

This decline is particularly notable among young voters, the demographic that Warren currently leads. Sanders is at just 11 percent with voters aged 35 or younger in the latest poll, compared to 16 percent in June and 25 percent in March.

Warren may have cut into this key constituency, which helped Sanders threaten his rival Hillary Clinton in 2016, notes the Des Moines Register. Only a quarter of those who caucused for Sanders in 2016 say they will do so again; 32 percent have indicated that they will instead support Warren.

In a race where voters are presented with many more candidates than they were in 2016, all candidates are forced to work hard to stand out. The new figures, though, suggest old favorites like Biden and Sanders may need to do much more if they want to rise to the top.