For a second straight night in Miami, the political prospects of "Medicare for All" dominated stretches of the debate as candidates sparred over its cost, the radical overhaul that would be required to make it a reality, and whether support for a single-payer system would scare off moderate voters the party is banking on to boost its fate in 2020.

But for all the sharp and sometimes shout-y exchanges, there was one thing that no one on the stage disputed: the end goal. Universal coverage in the United States is now the default position of the Democratic Party's top presidential hopefuls -- even for those whose actual plans may not achieve it.

The questions going forward are about ambition and, most pointedly, process. Some candidates prefer a path that preserves a place for private insurance. Others, like Sanders, would do away with them as soon as possible.

Others prefer a path that preserves a place for insurers, primarily by adding a public option to the Affordable Care Act exchanges. Even the harshest critics of Medicare for All -- former Maryland Rep. John Delaney and former Colorado Gov. John Hickenlooper -- argue that their plans would cover anyone and everyone who wants it, even though the public option proposals would have a more limited impact than Sanders' ambitious plan.

The shift among Democrats began before Sanders became a household name during his 2016 primary run. Hillary Clinton and Barack Obama, when they faced off in 2008, debated the details of a policy that ended up becoming the Affordable Care Act. Generations of Democrats of have toyed with ideas for expanding or guaranteeing coverage. But it is Sanders' relentless push for Medicare for All -- a proposal with 14 Senate co-sponsors in its latest iteration -- that has set a measuring stick among Democrats in this primary.

Former Vice President Joe Biden is among the group of Democrats who openly oppose Sanders' plan . But for him, too, the stated objective is to cover every American through a system rooted in law. In Biden's case, that means expanding the Affordable Care Act.

"The fact of the matter is that the quickest, fastest way to do it is build on Obamacare, to build on what we did (during the Obama administration)," Biden said. "And, secondly, to make sure that everyone does have an option. Everyone, whether they have private insurance or employer insurance and no insurance, they, in fact, can buy in, in the exchange to a Medicare-like plan."

The questions candidates face over the policy have also matured. And the bar, for those who want to project their support, has risen -- or become more clearly defined. On both debate nights, moderators asked for a show of hands from those who wanted to eliminate private insurance as part of their road to achieving universal coverage. For activists, this is where the rubber meets the road -- the answer, for those who say yes, that will invite the harshest blowback. On Wednesday, Sen. Elizabeth Warren -- who then said "I'm with Bernie on Medicare for all" -- and New York Mayor Bill de Blasio raised their hands.

Sanders, who has made clear that any lesser step would fail to realize his goal, and Sen. Kamala Harris did the same a night later. (Harris has since said she misheard the question; she would be willing to give up her own private insurance but would not get rid of the industry.)

Hickenlooper has been one of Sanders' most vocal critics. He warned, again, on Thursday night that the Vermont senator's agenda and embrace of democratic socialism risked opening up the entire field to unwarranted Republican attacks.

But when he began to speak about health care, even Hickenlooper opened with a line that Sanders so often uses himself.

"I believe that health care is a right and not a privilege," he said, before launching his rebuttal, arguing that "you can't expect to eliminate private insurance for 180 million people, many of whom don't want to give it up. In Colorado, we brought businesses and nonprofits together, and we got near universal health care coverage."

Like his fellow Centennial State Democrat, Sen. Michael Bennet does not support Medicare for all. But when he was invited to criticize Sanders on the issue, Bennet moved swiftly along to his own plans.

"I have proposed getting to universal health care, which we need to do. It is a right. Health care is a right," Bennet said. "We need to get to universal health care. I believe the way to do that is by finishing the work we started with Obamacare and creating a public option."

The choice, he added, "would be like having Medicare for All."

New York Sen. Kirsten Gillibrand jumped in when Bennet escalated his argument against Medicare for All, noting that she helped write a piece of the legislation -- its four-year phase-in plan -- and argued that it "merges what the (Sanders and Bennet) said."

Despite keeping her hand down when the candidates were asked about abolishing private insurance, Gillibrand has -- after Sanders -- the longest track record of supporting a single-payer program.

"In 2005, when I ran for Congress in a 2-to-1 Republican district, I actually ran on Medicare for all, and I won that 2-to-1 Republican district twice," Gillibrand said. "And the way I formulated it was simple: anyone who doesn't have access to insurance they like, they could buy it at a percentage of income they could afford."

The argument over the best -- and least politically dangerous -- process for achieving universal coverage has, for many of the candidates, now overtaken whether or not it is desirable or even feasible. And it has led some of the rivals to overstate how closely their proposals hew to Sanders' grand plan.

"Everybody who says Medicare for All, every person in politics who allows that phrase to escape their lips has a responsibility to explain how you're actually supposed to get from here to there," South Bend, Indiana, Mayor Pete Buttigieg said, before explaining his preferred path forward.

"It's very similar, I would call it 'Medicare for all who want it,' " he said. And it would begin, Buttigieg explained, with some "flavor" of Medicare being offered as an option to every American.

The result, he said, would be "a very natural glide path to the single-payer environment."