By Katie Lobosco, CNN/StyleMagazine.com Newswire

Free college is emerging as the new hot topic on the 2020 campaign trail.

The term, which Vermont Sen. Bernie Sanders helped make mainstream during his previous presidential bid, has become a catchall for a variety of plans aimed at making college more affordable.

"Some version of free or debt-free college -- or a bold proposal on college affordability -- is now the barrier to entry into this conversation," said Mark Huelsman, associate policy director at the liberal think tank Demos.

Massachusetts Democratic Sen. Elizabeth Warren unveiled a new plan Monday that would make tuition and fees free for all students at public colleges -- while also expanding financial aid so that it can be used to cover additional costs like housing, food, books and child care for students who need it.

She wants to invest an additional $100 billion in Pell grants over the next 10 years, making them available to more students and increasing the size of the award. Currently, the lowest-income students are eligible to receive about $6,200 a year from the federal Pell program.

Warren's plan goes even further than making college more affordable to help those who already have student debt -- differentiating herself from the rest of the field.

It would cancel up to $50,000 in student loans for households that make less than $100,000 a year, with the amount of relief getting gradually smaller as income level goes up. Households that make more than $250,000 would not be eligible for any debt relief.

She explained her reasoning for the proposal at her CNN town hall on Monday night.

"This is the America we live in now," she said. "Basically to get a shot at a middle class life you've got to have some post high school technical training, two-year college, four-year college, maybe graduate school depending on who you are and what you're ending up doing. The position of the federal government has been, good luck to you, you're on your own. The one thing they've done, they have ... lent tens of thousands of dollars to students."

"It is crushing them."

Several candidates have already expressed support for making sure students can graduate without debt. Last month, Sens. Cory Booker of New Jersey, Kamala Harris of California, Kirsten Gillibrand of New York and Warren -- all presidential contenders -- signed on to co-sponsor Hawaii Democratic Sen. Brian Schatz's Debt-Free College Act. It would establish a mactching grant to states that commit to helping students pay for the full cost of attendance -- including tuition, books and other expenses -- without taking out loans.

Tackling those other expenses differs slightly from Sanders' proposals, which focus more on making tuition and fees free at public colleges. His 2015 proposal offered to make those free for everyone, but a 2017 bill scaled back eligibility based on income -- its language built on a compromise proposal agreed on between Sanders and Hillary Clinton during the 2016 election.

His legislation would make community college free and four-year public colleges free for students whose families earn less than $125,000. It would also ensure that low-income students could still use federal Pell grants for books, housing, transportation and other expenses.

But not every candidate is embracing free college.