Warren surges to top spot in Iowa poll

Sen. Elizabeth Warren has overtaken 2020 rival Joe Biden in Iowa to snatch the lead in a Des Moines Register/CNN/Mediacom Iowa Poll of preferred Democratic presidential candidates published Saturday night.

Why it matters: Per the Des Moines Register, this is the first time Warren has led in the state's poll. It's the latest in a series of surges in the polls for the Massachusetts senator. She's also been drawing big crowds in recent weeks.

• Warren drew her largest campaign rally crowd of the 2020 cycle last Monday, when more than 20,000 people flocked to see her at Washington Square Park in New York City.

By the numbers: The poll of 602 likely Democratic caucusgoers was conducted Sept. 14-18, with a margin of error of plus or minus 4 percentage points. 22% of those polled say Warren is their pick for president. Former Vice President Biden is second with 20% and Sen. Bernie Sanders is the next closest at 11%.

Yes, but: While Warren and Biden appear to have pulled away from the rest of the Democratic presidential pack in Iowa, 63% of those polled said they could still change their mind after picking a top choice. Just 20% said they were decided on a first-choice candidate.

The big picture: Warren surged to the top of the Iowa poll as she joined 16 other Democratic presidential candidates at the state's annual Polk County Steak Fry in Des Moines, which drew a crowd of more than 12,200, according to the organizers, the Polk County Democrats.

• Warren won the biggest applause at the event, for reiterating her call for President Trump to be impeached, the New York Times reports.

Go deeper:

• Enthusiasm for Elizabeth Warren surges in new 2020 poll
• Warren is the only winner in polls after previous Democratic debates
• What you need to know about the 2020 presidential candidates, in under 500 words
  

Editor's note: This article has been updated with new details throughout.