Former Rep. Beto O’Rourke said on the debate stage Tuesday night that Americans who refuse to turn over banned semiautomatic rifles under his mandatory gun buyback program would be met with unspecified “consequences,” a stance which drew major pushback from his fellow Democratic contenders.

The Texas Democrat didn’t get into much more detail, but made clear that police would exercise force to confiscate weapons banned under his plan, the most sweeping gun control proposal offered by any Democratic presidential candidate.

“If someone does not turn in an AR-15 or an AK-47... then that weapon will be taken from them,” O’Rourke said. “If they persist, there will be other consequences."

Every candidate who addressed the issue on Tuesday evening supported additional restrictions on the sale of so-called assault weapons, but none went as far as O’Rourke. And his proposal prompted a harsh rebuke from others, especially South Bend, Indiana, Mayor Pete Buttigieg.

“Congressman, you just made it clear you don’t know how this is actually going to take weapons off the streets,” he told O’Rourke. “I don’t need lessons from you on courage, political or personal. The problem is not other Democrats who don’t agree with your particular idea of how to handle this. The problem is the National Rifle Association and their enablers in Congress, and we should be united in taking the fight to them.”

That drew a heated response from O’Rourke, who accused Buttigieg of minimizing the problem of gun violence and the toll it’s taken on victims of mass-casualty shootings.

“When you, mayor, describe this policy as a shiny object, I don’t care what that meant to me or my candidacy,” O’Rourke shot back. “But to those who have survived gun violence, those who have lost a loved one to an AR-15 or an AK-47, marched for our lives, formed in the courage of students willing to stand up to the NRA and conventional politicians and poll-tested politicians, that was a slap in the face to every one of those groups and every survivor of a mass casualty assault.”

O’Rourke’s proposal would likely require a massive police mobilization to enforce the confiscation of millions of firearms targeted by the plan. And that raised concerns for other candidates on the stage.

“In the place I grew up in, we weren't exactly looking for more reasons for cops to come show up at the door,” said Julian Castro, the former secretary of the Department of Housing and Urban Development. “I am not going to give these police officers another reason to go door-to-door in these communities.”