DETROIT, Mich. — The second round of the Democratic primary debates saw far-left candidates fending off skepticism from their more moderate opponents — when any of them could get a word in edgewise over the moderators.

Ten White House hopefuls — just half of an over-stuffed field — spent as much time discussing health care, immigration and gun violence as they did tripping over each other and the trio of CNN hosts with pleas for more time.

“Please respect the rules,” was a frequent admonishment delivered throughout the night by moderators Jake Tapper, Dana Bash and Don Lemon, with most candidates on the receiving end at some point.

“No,” a fed-up Massachusetts Sen. Elizabeth Warren finally pushed back at one point in the debate’s third act, shaking her head as she persisted to rebut an attack.

Those tightly enforced rules, intended to keep a leash on the crowded field on stage at Detroit’s Fox Theatre, allotted 60 seconds to answer a direct question, and a scant 30 seconds for responses and rebuttals to direct call-outs.

What filtered through to millions of viewers at home through the often stilted format was the ideological and generational gulf separating Warren and fellow uber-liberal Sen. Bernie Sanders, of Vermont, from their eight more moderate — but lower-polling — opponents.

“I think Democrats win when we run on real solutions, not fairy-tale promises,” said former Maryland Rep. John Delaney, in a not-so-veiled broadside of Warren and Sanders’ ambitious platforms, which include universal health care and forgiveness of student debt.

“I don’t understand why anybody goes to all the trouble of running for president of the United States just to talk about what we really can’t do and shouldn’t fight for,” parried Warren, showing her fire wasn’t just reserved for the moderators with a response that drew raucous applause.

Sanders offered a similar dream-big sentiment, saying, “I get a little bit tired of Democrats afraid of big ideas.”

South Bend, Ind., Mayor Pete Buttigieg — who, at just 37, repeatedly positioned himself as the party’s youthful face of the future — urged the field to focus on sharpening the best policy, not a policy that can be sold to Republicans.

“It’s true that if we embrace a far-left agenda, they’re going to say we’re a bunch of crazy socialists,” said Buttigieg. “If we embrace a conservative agenda, you know what they’re going to do? Say we’re a bunch of crazy socialists.”

That call for a unified vision came in response to a question about universal Medicare, the first of the big ideas on which the candidates sparred.

Ohio Rep. Tim Ryan tried to undercut Sanders’ insistence that his “Medicare for All” proposal will guarantee dental care, hearing aids and eyeglasses for seniors, interrupting, “You don’t know that, Bernie.”

“I do know!” snapped the famously irascible Vermont Democratic socialist. “I wrote the damn bill!”

The pair clashed again in the debate, when Sanders pointed out that polls have him topping President Trump in the 2020 race.

“Hillary Clinton was winning in the polls, too,” chided Ryan.

Despite the fleeting flashes of fireworks, it was the restrictive format that ruled at the expense of back-of-the-pack candidates, which included former Colorado Gov. John Hickenlooper, Montana Gov. Steve Bullock, Minnesota Sen. Amy Klobuchar, former Texas Rep. Beto O’Rourke and self-help author Marianne Williamson.

“I think the debate was rigged to a certain extent, and designed to give Elizabeth Warren and Bernie Sanders more air time than the rest of the candidates so that they couldn’t get their message out,” said Fletcher Smith, a former South Carolina State Rep. who’s endorsed Ryan.

“It looks like those people who were actually conducting the debate wanted to promote the winners that they were trying to pick.”

Many of the millions of viewers watching at home skewered the format on social media.

“The time limit is horrible,” tweeted @SandraCoppola7. “I stopped watching when I realized no one could finish an answer to a question.”

Joked another viewer, “Jake Tapper is going to TURN THIS DEBATE RIGHT AROUND AND GO HOME if the candidates don’t adhere to the time limits.”

Wrote a third watcher, “This format is a disaster.”

One viewer who resisted the urge to chime in was Trump.

The president — who tweeted during last month’s first debate in Miami that the proceeding was “BORING!” — told reporters that he would be watching the follow-up match, but sat on his fingers throughout Tuesday’s meandering two-and-a-half-hour spectacle.

The topic of climate change presented another ideological fork in the road, with former Colorado governor Hickenlooper blasting the lofty jobs promises in the proposed “Green New Deal.”

“You might as well FedEx the election to Donald Trump,” cracked Hickenlooper.

Bullock — a late entrant not part of the first debate — said the first step in the fight was to win the minds of GOP lawmakers.

“Let’s not just talk about plans that are written for press releases that will go nowhere else if we can’t even get a Republican to acknowledge that the climate is changing,” said Bullock.

One issue that yielded somewhat more cohesion — just days after three people, including two children, were killed in a California mass shooting — was gun control.

“This is not just about a system, this is not just about words, this is about the NRA,” said Minnesota Sen. Amy Klobuchar, vowing the take on the deep-pocketed National Rifle Association’s sway in the Beltway that has hamstrung overtures towards reform.

Agreed O’Rourke, “In this country, money buys influence, access and, increasingly, outcomes.”

Outsider option Williamson tried to expand the discussion of money in Washington to the need for campaign finance reform, saying that voters will rightfully offer a skeptical “yada yada yada” to any candidate who takes sizable lobbyist funding.

Ten more candidates will take the stage Wednesday night.

They include presumptive front-runner and former Vice President Joe Biden, California Sen. Kamala Harris and a trio of tri-state leaders: New Jersey Sen. Cory Booker, New York Sen. Kirsten Gillibrand and the Big Apple’s Mayor Bill de Blasio.

Additional reporting by Tamar Lapin and Nolan Hicks