In the last few months, Hamilton , a progressive economist at Ohio State University, has fielded calls from staffers for potential Democratic presidential contenders including Sens. Kamala Harris, Bernie Sanders, Cory Booker and Kirsten Gillibrand. They want to know more about ideas Hamilton has been developing for years, like a federal jobs guarantee and " baby bonds " designed to give every kid a nest egg heading into adulthood.

"I've had this vision for a long time," said Hamilton, who speaks with a preacher's zeal about the moral imperative of fighting racial and economic inequality. "It is amazing that at this moment that we are considering more transformative, bolder policies."

Hamilton isn't alone. The nascent 2020 campaign is shaping up to be all about radical ideas on the left, with candidates looking toward a populist, progressive agenda that's distinct from the centrist politics of previous election cycles.

That means that, all of a sudden, the academics who've been quietly working on those ideas for years now are finding an eager audience. Take University of Georgia law professor Mehrsa Baradaran, who has long advocated for allowing the US Postal Service to function as a bank in order to create a public option for financial services — an idea USPS has indicated it would be open to pursuing.

"It turns out that there are too few people doing this stuff, because there hasn't been a market for it," Baradaran said. "And all of a sudden, you go from nobody reading it, to Warren adopts it, to the Post Office adopts it, to Gillibrand adopts it."

"I'm very busy right now," she added. "I'm in DC a lot."

New policies for new problems

The swing left didn't come out of nowhere.

Beginning with the 2008 financial crisis, a new body of research percolated that shows the causes and consequences of economic stratification, upending the notion that simply growing the pie will allow everyone to have a bigger slice.

Funding and promoting a lot of that research has been Heather Boushey, who runs the Washington Center for Equitable Growth, a think tank focused on inequality that launched in 2013 as a startup within the Center for American Progress and later struck out on its own with funding from major foundations.

"Even in 2008, there was this sense that we were playing from a very old songbook in terms of how the economy works: If you focus on productivity, everything will be fine, and the role of government is to help markets work and get out of the way," said Boushey. "What you're seeing now is that a lot of people are saying that doesn't seem to be true. "

The shift began in earnest with the 2013 publication of French economist Thomas Piketty's book Capital in the 21st Century, which charted the rise in wealth inequality and argued that it is self-perpetuating. Since then, a team led by Harvard economist Raj Chetty has illustrated how a child's financial future is more closely linked to the zip code where she was born than almost any other factor -- undermining the whole notion that America offers equal opportunity to anyone who works for it.

Work by MIT's David Autor and co-authors illustrated the pernicious effects of trade liberalization with China on American manufacturing, playing into the sense of despair and resulting opioid addiction that has wracked industrial communities. Spiraling housing prices have collided with the rising cost of college, leaving an indebted generation with little hope of buying homes.

And a number of papers have documented how corporate mergers have reduced competition and new business formation, as well as led to lower wages by giving workers fewer job options.

All of these increasingly well-understood problems — which are most pronounced for people of color — have prompted calls for bigger solutions by Democratic politicians and activists, including not just presidential aspirants but members of Congress like freshman New York Rep. Alexandria Ocasio-Cortez.

The new guard wants to create a federal job for anyone who wants one and give a universal basic income to every US citizen, not just raise the minimum wage to $15 and bulk up the Earned Income Tax Credit. They also want to fund government programs to build low-income housing and renewable energy infrastructure, rather than just expanding market-based incentives; or break up the big tech monopolies, rather than just fine companies for misbehavior.

One of the most buzzed-about proposals in recent weeks has been Warren's plan for a 3% annual tax on assets for people with more than $50 million, which springs from the idea that taxation is a tool of mitigating inequality and redistributing capital. The tax would fund concrete benefits, like her proposed childcare centers.

Warren's team rolled it out with a custom-made analysis from economists Gabriel Zucman and Emmanuel Saez of the University of California-Berkeley, who have both worked with Piketty to compile empirical evidence around inequality and tax evasion.

Stephanie Sterling is vice president for advocacy and policy at the Roosevelt Institute, another progressive think tank founded in the last decade within an older non-profit affiliated with the federally-run Roosevelt Library. Its staff and fellows have also been consulting with progressive candidates, building the case that taxes aren't just for raising revenue.

"What we're seeing is the way that raising taxes on the wealthy can both de-concentrate their power and can serve to shift incentives towards the creation of productive private investment," Sterling says.

Personnel is policy

Despite what seems like an explosion of new candidacies and ideas, it's still very early in the 2020 cycle. Most campaigns don't have a dedicated policy staff yet and are building their platforms on top of legislation workshopped during candidate's day jobs. When contacted for this story, most either did not respond to requests for comment or referred CNN to outside experts whom they consulted in shaping legislation, though Gillibrand's Senate office responded with praise for Hamilton.

"Senator Gillibrand had a wide-ranging and meaningful discussion with Darrick Hamilton about many of his bold, progressive ideas aimed at addressing systemic and generational income inequality, which is often predicated on race," said spokesperson Whitney Mitchell Brennan. "She really enjoyed the conversation, they agreed about a lot, and she wants to continue to stay in touch."

So far, the candidate with the most advanced policy operation is Warren, who has already stacked up an arsenal of bills that haven't gone anywhere in the GOP-led Senate but will likely now serve as the core of her 2020 platform, especially as staffers move from her Hill office over to her campaign.

That process has already started. A Warren banking committee staffer who for the last five and a half years shepherded many of those proposals, Bharat Ramamurti, just moved over to her campaign.

Eventually, these are the types of people who could end up becoming the next chair of the Council of Economic Advisers or National Economic Council, steering policy in the post-Trump era.

"That's kind of the job of a good policy adviser in the campaign. You're not the driver. Dale Jr. is the driver. Your job is to get some tires on there." Austan Goolsbee

Once a candidate emerges as a likely nominee, wonks start piling in, hoping to style themselves as advisers and surrogates in order to land a job in the White House down the road.

For anyone who aspires to play that role, Austan Goolsbee — an economist who became one of the first advisors to then-Senate candidate Barack Obama — cautions that campaign jobs aren't all about crafting the best possible policy white paper, like you can from a post at a university. In politics, it's about talking points and crisis management.

"If you ever watch a NASCAR race, they pull the car in, and five people jump over the wall and they get them back out on the road in 13 seconds," Goolsbee says. "And that's kind of the job of a good policy adviser in the campaign. You're not the driver. Dale Jr. is the driver. Your job is to get some tires on there."

The center persists

Of course, not everybody is on board with the leftward drift in Democratic politics.

Established idea factories in Washington on the center left and the center right have been circling the wagons, to propose ideas that both contrast with the Trump agenda and address mounting concerns about inequality without getting too far out of what they see as the electorate's comfort zone.

Their potential vehicles include comparative moderates like Joe Biden and Amy Klobuchar, who hew closer to traditional market-centered Democratic policies.

Centrist think tank Third Way has put out a 2020 platform including proposals like more apprenticeships, employer-supported private retirement accounts, and a surge of investment in rural broadband.

The group's vice president for policy, Jim Kessler, argues that the Democrats who won in the 2018 midterms did so in suburban districts on bread-and-butter issues like healthcare and basic decency.

"I think there's an exhausted majority out there, looking for something bold but normal," Kessler says. "It's putting guard rails around capitalism, it's not rejecting capitalism and doing a demolition job."