New York City Mayor Bill de Blasio (D) attacked former Rep. Beto O’Rourke (D-TX) Wednesday night during the Democrat presidential debates, asking why he was defending private health insurance.

O’Rourke was asked a question on Wednesday why he supports a public option over the single-payer Medicare for All. O’Rourke’s public option plan would automatically enroll every American that does not have health insurance in Medicare.

A public option would allow some, or all, Americans to choose a government health insurance plan, such as Medicare or Medicaid, while allowing private health insurance plans to compete against the public option.

“If you’re uninsured, we enroll you in Medicare,” O’Rourke explained.

“I think that choice is fundamental to our ability to get everybody health care,” the Texas Democrat added.

“You deserve choice,” O’Rourke said.

Mayor de Blasio, who backs Medicare for All, went after O’Rourke, suggesting that private health insurance remains too expensive for millions of Americans.

Medicare for All, most notably pushed by 2020 candidate Sen. Bernie Sanders (I-VT), would eliminate private health insurance and replace it with an expanded Medicare system that would cover all Americans and even illegal immigrants.

The New York Democrat said, “Private insurance is not working for tens of millions of Americans when you talk about the co-pays, the deductibles, the premiums, the out-of-pocket expenses, it’s not working. How can you defend what’s not working?

“Why are you defending private insurance, to begin with,” De Blasio asked O’Rourke.

Sean Moran is a congressional reporter for Breitbart News. Follow him on Twitter @SeanMoran3.