INDIANOLA, Iowa — There may be no surer sign that a campaign is gaining traction than when its opponents begin to attack.

ADVERTISEMENT

Polls show Buttigieg rising into the top tier of candidates, alongside some whose political careers began before he was born.

"We need to nominate a candidate who can appeal to the African American and Latino communities," former Housing and Urban Development Secretary Julián Castro told The Hill here on Sunday, after warning his party against nominating "what seems like the safe choice."

The polls that show Buttigieg on the rise also show his support comes almost entirely from white Democrats. He has yet to earn an infusion of support among African American voters, and Castro said Buttigieg's record is why.

"Just look at his track record as mayor. He has a bad track record with African Americans on the issues, and he's almost acknowledged as much," Castro said. "It is risky to nominate somebody that cannot appeal to one of our most important constituencies."

Touring Iowa on a campaign bus, Buttigieg acknowledged problems in South Bend. Earlier this year, Buttigieg took several days off the campaign trail to return home after a white police officer shot and killed an unarmed black man.

But on Sunday he pushed back hard against Castro.

"Look, our city has had a lot of challenges, but the black voters who know me best have returned me to office and supported me more the second time around than the first, and I would be happy to walk him around South Bend and introduce him to folks if he'd like to learn how we tackled these really tough issues," Buttigieg told a CNN reporter.

"We've had major challenges, as diverse communities do, around policing and economic inequality, but they're not going to be made better by being used as a political football. These are community challenges that we're facing together," he said.

Buttigieg said Harris was right.

"I think we all know that this is a fluid race, that it's a very competitive race and that anything could happen," Buttigieg told reporters on his bus Sunday.

Buttigieg has shown few qualms about launching his own broadsides in recent weeks, taking particular aim at Warren both on the debate stage and at a major dinner for Democratic activists on Friday in Des Moines.

In debates, he has questioned Warren's "Medicare for All" plan. On Friday, without naming the Massachusetts Democrat, Buttigieg lumped her in with "the political warfare that we have come to accept from Washington, D.C."

"I will never allow us to get so wrapped up in the fight that we start to think the fighting is the point. The point is what's on the other side of the fight," Buttigieg said.

Half an hour later, Warren jabbed right back, suggesting that Buttigieg and others who offer anything less than her progressive platform would lose to Trump.

"Anyone who comes on this stage and doesn't understand that we are already in a fight is not the person who is going to win that fight. Anyone who comes on this stage and tells you they can make change without a fight is not going to win that fight. And anyone who comes on this stage and tells you to dream small and give up early is not going to lead our party to victory," Warren said.

"Mayor Pete has started to take the fight to other candidates and was pretty effective in scoring some points against Bernie and Warren in the last debate," said Doug Thornell, a longtime Democratic strategist who worked for Dean in 2004. "I think he is seen as a real threat, so the top tier ahead of him are trying protect what they’ve got and the candidates in tier two are trying to keep him in their ring."

ADVERTISEMENT

But, dangerously for them, Iowa Democratic voters look much more like Buttigieg's coalition than states like South Carolina, with its heavily African American constituency, or Nevada, which has a strong Hispanic contingent.

In a New York Times–Siena poll released over the weekend, Buttigieg's coalition is better-educated than average; he earns far more support among voters with a bachelor's degree or more than among those who did not go to college.

In a race that is largely becoming about a candidate's chances of beating President Trump, his deficit among working-class and minority voters is becoming a potent line of attack.

"We lost because people sat out the 2016 election," Castro said. "You have to excite the base of this party, bring new voters into the fold. And if you have a candidate that can't speak to a range of constituencies among Democrats, then we're going to lose this election."