CNN’s panel of moderators ― Tapper, Don Lemon and Dana Bash ― repeatedly used conservative concerns about liberal positions on health care, immigration, climate change and more to inform their questions. They also forced the more progressive front-runners to answer to the attacks of their less-prominent rivals ― and in some cases, vice-versa ― granting extraordinary airtime to candidates like Delaney and Bullock in the process.

But regardless, Sanders appeared to speak for other candidates onstage — including such other top contenders as Sen. Elizabeth Warren of Massachusetts, South Bend, Indiana, Mayor Pete Buttigieg and former Rep. Beto O’Rourke of Texas — who struggled for airtime against more moderate candidates who have barely registered in the polls ― former Rep. John Delaney of Maryland, Montana Gov. Steve Bullock and Rep. Tim Ryan of Ohio.

It was not clear whether Sanders was referring to Tapper’s queries about whether candidates would support middle-class tax hikes to pay for “Medicare for All.”

Tapper cut Sanders off at that point, saying that the senator’s time was up.

“Jake, your question is a Republican talking point,” Sanders said to applause at the Fox Theatre in Detroit. “And by the way, the health care industry will be advertising tonight on this program.”

Sen. Bernie Sanders (I-Vt.) took his criticism of the mass media to live national television on Tuesday night, accusing CNN’s Jake Tapper of amplifying GOP rhetoric on health care as 10 contenders for the Democratic presidential nomination squared off in a debate.

BRENDAN SMIALOWSKI/Getty Images The CNN questioners in Tuesday's debate among 10 Democratic presidential candidates gave a lot of airtime to moderates who are far behind in the polls, such as former Colorado Gov. John Hickenlooper (second from right) and former Rep. John Delaney of Maryland (far right).

Tapper’s first question to Sanders was a case in point, asking him to respond to Delaney’s criticism of Medicare for All. Delaney, Tapper noted, referred to single-payer health care “as bad policy” and “political suicide that will just get (President) Donald Trump reelected.”

Tapper then repeatedly pressed Warren on whether she would accept higher middle-class taxes to finance Medicare for All, interrupting her when she would not respond directly.

“Giant corporations and billionaires are going to pay more,” she said, implying that the elimination of out-of-pocket health care costs would provide savings that would more than make up for any tax hikes. “Middle-class families are going to pay less out of pocket for their health care,” she said.

Tapper next gave Bullock time to explain why he opposed Medicare for All, letting the Montana governor speak uninterrupted. Tapper did not challenge him on whether merely adding a public option, as Bullock has said he wants to do, would ensure universal coverage and bring down costs.

Tapper then turned to Buttigieg, who also supports a public option in the form of a Medicare buy-in, asking him whether he supported raising middle-class taxes to expand coverage. There is nothing about giving Americans the opportunity to buy into Medicare that would necessarily cost the federal government money, and Buttigieg initially ignored the point.

But Tapper followed up with him, seeking clarification on the matter.

“I think you can buy into it. That’s the idea of Medicare for all who want it,” Buttigieg responded. “Look, this is a distinction without a difference, whether you’re paying the same money in the form of taxes or premiums.”

When it came to the question of whether to turn unauthorized border-crossing into a civil offense, rather than a criminal one, Tapper and his team again played the prosecutors.

Bash turned to Ryan, who casts himself as a representative of the predominantly white, industrial heartland drifting away from the party, to respond to Republican-style fears about bigger social benefits attracting more unauthorized immigration.

“Congressman Ryan, are Sen. Sanders’ proposals going to incentivize undocumented immigrants to come into this country illegally?” she asked.

“Yes, and right now if you want to come into the country, you should at least ring the doorbell,” he replied.

When the conversation shifted to foreign policy, Tapper was eager to press the candidates on whether they would be willing to rule out using nuclear weapons preemptively.

He began with Warren, who has endorsed the U.S. foreswearing a preemptive nuclear strike, pressing her on why the nation “would tie its own hands” in that way.

“Because it makes the world safer,” she responded. “The United States is not going to use nuclear weapons preemptively and we need to say so to the entire world.”

This story has been updated with the question on the use of nuclear weapons.