Ms. Warren has also sought to portray herself as a consensus candidate, airing a commercial that features Iowa supporters of Mr. Sanders, Hillary Clinton and Mr. Trump from 2016 who all say they are now supporting the Massachusetts senator.
And in a plain acknowledgment of voters’ concerns about sexism in the general election, Ms. Warren released another spot showing a former supporter of Mr. Trump — an older man from rural Iowa — directly addressing worries among some voters about nominating a woman. “For people that say that a woman can’t win, I say: nonsense,” he says, holding up a photograph showing a Trump sign and declaring: “This is the man to beat, and Elizabeth can do it.”
At a kickoff event for Warren canvassers on Friday morning in Clive, a suburb of Des Moines, Michelle Wu, a Boston city councilor, urged them to reassure anxious voters with a version of that argument, stressing Ms. Warren’s victory in 2012 over a popular Republican senator — the “barn jacket-wearing, pickup truck-driving Scott Brown” — and promising that her economic message would appeal to independents and disaffected Republicans.
Not to be outdone on electability is Ms. Klobuchar, who for months has been blunt about why Iowans should turn to her: because she’s won every race she’s run in an increasingly competitive Midwestern state, Minnesota.
While that pitch has made her competitive in Iowa, she has been outspent and has polled below the four leading Democrats.
In the campaign’s closing days, Ms. Klobuchar, too, is becoming even less subtle: She has printed T-shirts in her signature green reading, “Amy Klobuchar Will Beat Donald Trump.”
Patty Wood, a Sioux City voter who came to see Mr. Buttigieg there Friday, said she was weighing Ms. Klobuchar but was mostly confused about what she called her “top priority” — beating Mr. Trump.