(CNN) Emboldened by a base thirsty for bold new initiatives, ambitious Democrats have spent large chunks of the Trump era building and working out how to sell a slate of unapologetically progressive policy programs.

Now, as the 2020 presidential primaries come into sight, yet another new front is emerging. Over the last two weeks, a growing roster of potential candidates for the Democratic nomination have stated or affirmed their support for some form of legislation that would guarantee a job to every American.

The party's left flank has, for decades, sought to advance universal solutions to perennial problems. Since President Donald Trump's election, which sealed Republicans' grip on power in Washington, Democratic politicians and policymakers, along with one notable independent senator, are moving toward that vision -- creating a new framework for how the party might operate if it can regain the White House and congressional majorities over the next two years.

Menu of proposals

Last Friday, New Jersey Sen. Cory Booker unveiled plans for a bill would create more than a dozen pilot programs, each running for three years, in "high-unemployment communities and regions" around the country. If successful, their models could help set the standard for a wider-reaching program.

"Not only would this have a positive impact on the lives of potentially hundreds of thousands of Americans right away," Booker said in a statement, "but the valuable data gathered would help us learn lessons, assess its effectiveness, and perfect the idea."

Then, on Monday, the Washington Post first reported that Vermont Sen. Bernie Sanders was preparing his own, more comprehensive plan. New York Sen. Kirsten Gillibrand, another potential 2020 contender, has been on the record since March with her support for a federal jobs guarantee, a position she repeated last week.

If Republicans could give $1.5 trillion in tax cuts to corporations and the wealthiest among us, why can't we invest a similar amount in a guaranteed jobs plan for regular Americans who are unemployed and willing to work to better their local community? — Kirsten Gillibrand (@SenGillibrand) April 17, 2018

The parameters of Sanders' forthcoming bill are broad and simple.

"Under a federal jobs guarantee program, the U.S. government would guarantee a job with a living wage and good benefits to any resident who wants or needs one," a draft proposal reads.

Though still a work in progress, it would guarantee wages of at least $15 an hour, indexed to inflation by the program's fourth year, offer retirement and health benefits on par with other federal employees, child care assistance and 12 weeks of paid family leave. The jobs listed include everything from park maintenance to construction work and home care.

But there are also loftier ideals in play. The draft describes what would be a massive new entitlement as "more than simply an economic fix."

"People working under the federal job guarantee will be serving their communities and their country, uniting use together in a common purpose, rebuilding the social fabric of our nation," it reads.

The lefty wonks have their say

Research published for the Center on Budget Policy Priorities by William Darity Jr., a professor of public policy at Duke University, New School economist Darrick Hamilton and Duke postdoctoral associate Mark Paul has been influential in shaping both the Sanders and Booker plans. In an interview with CNN, Darity said he has also been in contact with the offices of Gillibrand and Oregon Sen. Jeff Merkley, both of whom, along with Sens. Elizabeth Warren of Massachusetts and California's Kamala Harris, are co-sponsors of the Booker bill.

The Federal Jobs Guarantee Development Act builds off of the #jobsguarantee program proposed by Roosevelt Institute Fellows @MarkVinPaul @DarrickHamilton and @SandyDarity. Read their full proposal here: https://t.co/7OwxMGlwSX — Roosevelt Institute (@rooseveltinst) April 20, 2018

"The domestic models (for these new bills) date back to the Great Depression, with the implementation of the Works Progress Administration and the Civilian Conservation Corps," Darity said. "What would be different about this type of a project is that it would be a universal program of employment -- everyone would be eligible to take advantage of this public option -- and it would be permanent."

Having spent a decade advocating for a job guarantee, Darity reasoned that President Donald Trump's election -- its "shock effect" -- was the blow that pushed mainstream Democrats in his direction. The party, he said, is no longer working under the illusion that Republicans would agree to any form of meaningful compromise and has stopped "self-censoring themselves before they put forth legislation to be considered."

The emerging jobs guarantee debate, like with health care, has tracked the broader left's ideological spectrum. Whether to pursue universal programs at the expense of means-tested or more narrowly targeted ones has roiled Democratic politics for ages. The question lay at the wonky core of the fissure that opened up during the 2016 presidential primary. Naturally, it looks set to divide minds over the prospects of a jobs guarantee.

In May 2017, the liberal Center for American Progress introduced a more modest plan , in scope and cost (at a projected $158 billion per year), which would focus on individuals without a college degree. By contrast, the model preferred by Sanders, as outlined by Darity and his colleagues, would be available to any working American. Neither Sanders or Booker has tallied up a price tag yet, but Darity estimated that a full guarantee would require upwards of $750 billion annually, with the average expenditure, per worker, figured at between $50,000 and $60,000. (CAP's estimate put the direct cost of each job at $36,000.)

Supporters of the universal approach note that in times of severe economic downturns, well-educated workers in professional roles are not immune mass layoffs. They also argue that the increased costs would be offset, or at least be made more palatable, by a resulting cut in unemployment insurance payments, an influx of tax money to state and local governments and the potential for a "consumption stimulus," as Darity described it -- an economic spark created by newly employed workers' new spending.

The case against

Stan Veuger, a resident scholar at the American Enterprise Institute, isn't so sure. He questioned the need -- unemployment is currently at 4.1%, its lowest level in almost 18 years, though that doesn't account for Americans who have stopped looking, effectively taking themselves out of the labor market -- and fretted over the knock-on effects the program could have on private businesses.

"Unemployment isn't as much of an issue as it was five years ago and long term unemployment numbers have come down," Veuger said. "It seems weirdly timed. The problems that still remain are much more localized. Then you get into the problem that if you are basically at full employment, they introduce a program like this, is you pull people out of regular private sector jobs into this program making private sector companies less competitive."

Other critics, like Moody's economist Adam Ozimek, rushed to the barricades when Booker's plan dropped last week. In a post on Forbes.com, Ozimek argued that a federal jobs guarantee would effectively nationalize "a quarter or more" of the US labor market and, more than a serious economic proposition, should be viewed as evidence that Democrats are fostering their own "tea party."

"It's really crucial not to lend credence to this insane idea by trying to water it down in a way that its promoters clearly don't intend," Ozimek wrote . "This is a GOOD JOBS program. The core idea is that the government should set a high labor standard and hire all those workers."

To which Darity, the Duke economist, might well nod in agreement. The jobs guarantee's potential effect on labor standards across the board is one of its backers' favorite selling points.

"This is not just about the number of jobs, but also the quality of jobs," Darity said. "We effectively place a floor on the quality of compensation that's provided not only by the public sector, but by the private sector. One of the intentional goals of the federal jobs guarantee is to eliminate bad jobs."