WASHINGTON — Freed from the constraints of power, Democrats are becoming a progressive ideas factory.

On issues like health care, immigration, jobs, and crime, once-fringe policy proposals are gaining traction with lawmakers, activists, and wonks as they debate the party’s path out of its current wilderness.

Democrats point to a few factors driving the progressive policy boom.

At the grassroots level, President Donald Trump spurred a restive base toward fiercer activism with a passion that has politicians worried about getting on their bad side. There’s also the rise of Bernie Sanders, whose policy DNA and loyal following is remaking the broader party.

And at the top, there’s a staring contest between potential 2020 presidential contenders, especially in the House and Senate, that has members looking for new ideas to distinguish themselves and wary of being left off standout legislation from rivals. Many of the bills described below are co-sponsored by the same pool of senators, including Sanders, I-Vt., Kamala Harris, D-Calif., Kirsten Gillibrand, D-N.Y., Cory Booker, N.J. and Sherrod Brown, D-Ohio.

Whatever the cause, here are five areas where left-leaning ideas are gaining ground among Democrats.

HEALTH CARE

This is the biggest shift. Top-tier Democratic candidates around the country, including some in conservative-leaning districts, are running on a promise of universal access to Medicare, with 2020 hopefuls are lining up to showcase their own plans.

There are still major gaps between competing proposals, especially when it comes to their price tags. The most far-reaching legislation, favored by Sanders and co-sponsored by 17 Democratic colleagues, would create a massive single payer system that replaces private insurance with a more generous version of Medicare. Other bills would allow individuals and, in some cases, employers to buy into a Medicare plan, which would compete with private sector options, and expand subsidies in the Affordable Care Act to help finance coverage. But the overall direction is clear: A robust, universally available, government health care plan.

“The conversation is not about whether Medicare for All is a good thing or not, but rather what’s the best way to get us there, which is a radically different place than where we were during the fight over the Affordable Care Act,” Stephanie Taylor, co-founder of the Progressive Change Campaign Committee, told NBC News.

JOBS

The hottest new topic in progressive circles is a proposal, backed by several of the Senate’s big names, to enlist the federal government to guarantee jobs for the jobless.

The Federal Jobs Guarantee Development Act, which Booker introduced in April, would set up a pilot program that provides jobs that pay at least $15 an hour in 15 urban and rural areas. Co-sponsors include Sens. Harris, Warren, Gillibrand, and Jeff Merkley, D-Ore.

Under the bill, local governments would apply for grants detailing how they would use the money. Those applications would be evaluated based on the level of economic distress in the area and how beneficial the proposal sounds.

Supporters believe this new public sector would compete with private companies for labor and push wages and benefits up everywhere. It would also provide targeted benefits to communities that are struggling the most, potentially helping to combat regional and racial inequality.

But the idea is highly controversial, even among left-wing wonks. For one thing, the cost is enormous: There’s no Congressional Budget Office score on the Booker bill, but Darrick Hamilton, an economics professor at the New School whose own jobs guarantee proposal helped inform framework for the bill, estimates his national version would cost $543 billion each year and up to $700 billion in a recession — roughly the same as the current defense budget.

BASIC INCOME

While not in direct opposition to the jobs guarantee, some critics favor an alternative proposal: Spending big money to subsidize wages at workers’ existing jobs through the tax code.

One bill, backed by Rep. Ro Khanna (D-Calif.) and Sen. Brown, would massively expand the Earned Income Tax Credit that would cover more families and provide a larger tax refund. The concept has garnered attention from wonks, including some libertarian-leaning thinkers, who have argued America needs to create a guaranteed basic income to deal with the challenges of automation and stagnating wages.

Under the Grow American Incomes Now Act (GAIN), working families with three children would receive up to about $12,131 a year (up from $6,318 today) and childless workers would get up to $3,000 (up from $510).

Khanna estimates the bill would cost $1.4 trillion. Taking a page out of the Republican playbook, he proposes paying for it with a promise of higher economic growth from working families spending their gains on American products.

In order to prevent corporations from using the tax gains to offer lower paying jobs — one common criticism of EITC proposals — he’d pair it with legislation raising the minimum wage to $15 and requiring corporations to help pay for government benefits if their employees qualify for programs like food stamps. Khanna is also introducing his own jobs bill that would offer grants for temporary employment aimed at training people for private sector jobs.

IMMIGRATION

Democrats evolved on immigration enforcement under President Obama, from emphasizing enforcement — he was once dubbed “deporter-in-chief” by activists — to taking actions like DACA to protect huge swaths of undocumented immigrants from removal.

In the Trump era, the administration has stepped up interior enforcement, begun to unravel DACA, pledged a crackdown on “sanctuary cities” that resist deportations, and opened up hundreds of thousands of longtime residents with Temporary Protected Status to eventual removal.

That’s created a greater sense of urgency from immigrant activists, many of whom are DREAMers themselves. They’re pushing Democrats to take a tougher stand against Immigration and Customs Enforcement, the agency that handles interior enforcement, and some Customs and Border Protection practices as well. New activist groups like Indivisible have taken up the cause too.

And they believe they're getting results. During negotiations over a spending deal, 83 House Democrats signed onto a letter pushing back against requests for increased spending on ICE and instead demanding reduced funds for deportations and detention facilities at the border, among other items. 19 senators signed onto a similar letter, including Sanders, Harris, Booker, and Warren. On Friday, Gillibrand introduced a bill requiring Border Patrol agents to document searches of buses and trains around the border and submit regular reports to Congress.

Last week, progressive sheriff candidates backed by national activists in Durham and Mecklenburg County in North Carolina also ousted incumbents while pledging to reduce cooperation with ICE.

Activist and commentator Sean McElwee has even garnered attention with an “Abolish ICE” campaign to get left-leaning candidates behind dismantling the agency entirely. While it's still far from a mainstream Democratic position, he scored a high-profile backer in congressional candidate Randy “Iron Stache” Bryce in Wisconsin.

“Even if it doesn’t end ICE, you can create a visceral negative reaction toward the organization,” McElwee said. “We win if people hate ICE enough that it hurts politicians to fund them.”

MARIJUANA

It was an image that would have seemed unthinkable a few years ago: Senate Minority Leader Chuck Schumer, D-N.Y. signing a bong in an appearance on VICE News — released ahead of 4/20 this year — announcing his support for a national bill decriminalizing marijuana.

When President Obama took office, questions about legalization were treated as a joke — but with states from Colorado to California to Massachusetts since passing recreational pot legislation, the party is at a tipping point. In New York, Gov. Andrew Cuomo denounced marijuana as a “gateway drug” earlier this year, but is moving closer toward legalization while facing a primary challenge from Cynthia Nixon, who has seized on the issue. In California, Sen. Dianne Feinstein, D-Calif. came out for legalization this month while also facing a progressive challenger. First-year Democratic Gov. Phil Murphy is already pursuing legalization in New Jersey. In the Senate, Harris signed onto Booker's legalization bill.

Of course, it isn't just a liberal issue. After the Trump administration threatened to crack down on states who legalized marijuana, Senator Cory Gardner, R-Col. led a blockade of Justice Department nominees to force the White House to back down. Recent polling by Gallup shows legalization enjoys broad majority support among the public.

“Overall, I think it's just a matter of federal lawmakers starting to listen to their constituents,” said Morgan Fox, communications director of the pro-legalization Marijuana Policy Project. "This is really bipartisan."

GO BIG OR GO HOME?

Some Democrats say Trump has changed the rules by making implausible, unworkable — but eye-catchingly ambitious — promises to voters, and that they need bolder ideas to steal the spotlight back. It doesn’t hurt that few on either side of the aisle seem to care about the deficit anymore.

But there’s risk too: The RNC is talking up an “alarming liberal radicalism” in press releases and sees an upside in defining Democrats as beholden to the far left. Raising voter expectations too high could also lead to disillusionment if those making the promises can’t deliver once in power.

So far, those concerns haven't stemmed the new wave of progressive pledges. “Not everything being discussed is going to fly, but it’s pretty clear to me the party is moving significantly to the left,” Jim Manley, a former Democratic Senate leadership aide, told NBC News. “Anyone running for president in 2020 is going to have to take a good, hard look at some of these ideas.”