Presidential candidate Pete Buttigieg on Tuesday responded to a voter's question about Bernie Sanders's campaign attacking other Democratic candidates, saying he does not measure the boldness of a campaign by how controversial its ideas are.

"Here’s my message to progressives, it's that I would be the most progressive president we’ve had in a half-century. It’s just that I don’t measure the boldness of an idea by how many people it puts off and how much controversy it generates," Buttigieg said during a town hall in Ottumwa, Iowa.

Buttigieg was responding to a question from a 15-year-old boy in the audience who expressed his discomfort with how the Sanders campaign treats the other presidential candidates—particularly its attacks on the more moderate Democrats.

"I really started to realize just how mean-spirited and really just how similar [Sanders’s campaign] is to the Trump campaign, about how much they slander former vice president Biden, Senator Warren, and even you," the boy said.

"Why should people who are really kind of leaning toward Bernie’s Medicare for All message listen to you, especially with how much misinformation his campaign puts out about moderate Democrats?" he asked.

Buttigieg said he is progressive enough for Sanders’s supporters but noted the policy differences between his Medicare for All Who Want It plan and Medicare for All, Sanders’s signature health care plan. Buttigieg said his proposal would solve the health care problem in the United States at a lower cost, arguing his and Sanders’s goals ultimately align.