The 2020 Democratic candidates are mostly on the same page — or at least the same bill — when it comes to tackling the student loan debt crisis.

Sens. Elizabeth Warren, Cory Booker, Kamala Harris, Kirsten Gillibrand and Rep. Tulsi Gabbard all endorsed Sen. Bernie Sanders' College for All Act in 2017. The $47 billion plan would eliminate undergraduate tuition and fees at public colleges and universities. It would also lower interest rates on student loans, and allow those carrying existing debt to refinance their loans.

Harris, Booker, Warren and Gillibrand have since signed on to Sen. Brian Schatz's Debt-Free College Act, which also addresses costs beyond tuition, such as books and living expenses. The Hawaiian Democrat's more ambitious plan carries an even larger price tag — an estimated $90 billion.

College debt in the United States has roughly tripled since 2006 and now exceeds $1.5 trillion, second only to mortgage debt. There are about 43 million student loan borrowers nationwide.

President Donald Trump, meanwhile, is pushing a provision that would cap the amount of federal aid a student could take out in a bid to halt runaway debt.

"Student loan debt. I'm going to work to fix it because it's outrageous what's happening. You're not given that fair start," the president said earlier this month. "We're going to work on that very soon. I've always been good with loans and — I love loans. I love other people's money."

The Democrats gunning for his job agree on the scope of the problem, but have different solutions. Here's a look at some of them:

Kamala Harris speaks during a town hall meeting at Canyon Springs High School on March 1, 2019 in North Las Vegas, Nevada. Ethan Miller / Getty Images file

Sen. Kamala Harris, D-Calif., a former prosecutor, has said she plans to go "after predatory private colleges" that lure students with empty promises of profitable jobs while leaving them in a pile of debt. A proponent of the Schatz bill, she has called the debt crisis "one of the biggest challenges facing our country" and is pushing for debt-free college and setting up a system for students to refinance their debt.

South Bend Mayor Pete Buttigieg arrives to speak about his presidential run during the Democratic monthly breakfast at the Circle of Friends Community Center in Greenville, South Carolina on March 23, 2019. Richard Shiro / AP

Mayor Pete Buttigieg has a personal stake in the student loan battle — his husband, Chasten, is a teacher with a master's degree that's "left us with a lot of debt." The South Bend, Indiana, mayor told Vice earlier this month that he'd like to improve accessibility to the Public Service Loan program, and expand the cap on how much debt is forgiven in the Teacher Loan Forgiveness program.

Amy Klobuchar speaks during a meet and greet with local residents on March 17, 2019, in Cedar Rapids, Iowa. Charlie Neibergall / AP file

Sen. Amy Klobuchar, D-Minn., has separated herself from her fellow 2020 candidates in the Senate by declining to sign on to either the College for All Act or the Debt-Free College for All Act. "I am not for free four-year college for all, no," the Minnesota senator told a CNN town hall in February. "If I was a magic genie and could give that to everyone and we could afford it, I would." Instead, she is in favor of extending and expanding Pell grants — federal student aid — and providing free two-year community colleges. She also wants to make it easier to refinance debt. She assured students at the town hall she had some idea about what they were going through. "My husband had tens of thousands of dollars in student loans, and I married him anyway," she said.

Kirsten Gillibrand, speaks at a campaign meet-and-greet in Clawson, Michigan on March 18, 2019. Paul Sancya / AP file

Sen. Kirsten Gillibrand, D-N.Y., has vowed that if elected president, she'd immediately move to allow borrowers to refinance loans down to a four percent interest rate. Gillibrand, who backs the Schatz bill, has been speaking out for years against the high interest rates that can hit student borrowers — she introduced her Federal Student Loan Refinancing Act in 2013.

Democratic presidential candidate and former Texas congressman Beto O'Rourke is introduced at a campaign stop at a home in Las Vegas on March 23, 2019. Chase Stevens / Las Vegas Review-Journal via AP file

Beto O'Rourke is proposing tuition-free community colleges — "You want to go to community college, you go without paying a single dime," he said at a town hall in South Carolina earlier this month. The former Texas congressman added that he also favors making public colleges and universities tuition free as well. "It will cost us a little bit up front, but it will produce a return far greater than that investment," he said.

2020 Democratic presidential candidate Sen. Cory Booker speaks during a meeting with local residents on March 16, 2019, in Ottumwa, Iowa. Charlie Neibergall / AP file

Sen. Cory Booker, D-N.J., is offering what he's said could be a long-term solution to the problem — establishing a savings account with $1,000 in it for every baby born in the U.S. Depending on family income, up to another $2,000 a year would be added to the account, which could be accessed for higher education payments or home ownership after the child turns 18. Booker's also co-sponsoring the Schatz bill, and has pushed for tuition-free community colleges, simplifying the student loan process and refinancing existing loans.

Supporters cheer as Sen. Bernie Sanders, I-VT, addresses the crowd at a campaign event in South Carolina on March 14, 2019. Sean Rayford / Getty Images

Sen. Bernie Sanders, I-Vt., made student loan debt the centerpiece of his 2016 campaign for president, and pushed eventual Democratic nominee Hillary Clinton to adopt his call for tuition-free public colleges and universities. The Vermont senator's College for All Act would establish a partnership with states to fund the measure, and he's also called for lowering the interest rate on student loans and enabling borrowers to refinance existing loans. The legislation would be funded by fees on Wall Street trades.

Elizabeth Warren speaks to local residents during an organizing event on March 1, 2019, in Dubuque, Iowa. Charlie Neibergall / AP file

Sen. Elizabeth Warren, D-Mass.,calls the student debt problem a "national emergency." She's signed onto Schatz's Debt-Free College for All Act, and has sought to enable borrowers to refinance their loans, introducing the Reduce Student Debt Act in 2016. A long-time law professor, the Massachusetts senator also introduced a bill to cap student loan interest rates in 2013. On the 2020 campaign trail, she introduced a plan that would offer free public college for future students while cancelling up to $50,000 in student debt for over 40 million Americans. The $1.25 trillion plan would be paid for in part by a tax on the super-rich.

Democratic presidential candidate Julian Castro speaks to students at Bell Gardens High School, in Los Angeles county, in Bell Gardens, California on March 4, 2019. Mario Tama / Getty Images

Julián Castro says he wants to ensure students learn important trade skills, and is focusing on community colleges and apprenticeship programs instead of four year colleges. "We'll work to make the first two years of college, a certification program or an apprenticeship accessible and affordable, so millions more people get the skills they need to get a good job without drowning in debt," the former Housing and Urban Development secretary said in January. As for existing student loan debt, he told Salon, "We need to erase it."

Tulsi Gabbard addresses a gathering during a campaign stop at a brewery in Peterborough, New Hampshire, on March 22, 2019. Charles Krupa / AP file

Rep. Tulsi Gabbard, D-Hawaii, was a co-sponsor of the House version of Sanders' College for All Act, which would make college tuition free for students from families earning $125,000 or less. The Hawaiian congresswoman was also a co-sponsor of the HELP for students and Parents Act, which would give tax credits to businesses that help employees pay off student debt.

Democratic U.S. presidential candidate U.S. Representative Eric Swalwell (D-CA) visits Torrent Brewing Company in Ames, Iowa, on April 11, 2019. Rachel Mummey / Reuters

Rep. Eric Swalwell, D-Calif., is another candidate with experience in student loan debt. "I have two kids under two. I'm paying off just under $100,000 of student loan debt," he told MSNBC in March. In Congress, he's introduced legislation to enhance student forgiveness for teachers, police officers and other public servants, as well as another bill that would allow student loans to be discharged in bankruptcy proceedings.

John Delaney speaks to an audience in Dover, New Hampshire on March 28, 2019. Nikolas Hample / Sipa USA via AP

John Delaney is a proponent of a "Pre-K through 14 education" model, adding on to the current kindergarten through grade 12 education. That would include making two years of community college or technical training part of public education. The former Maryland congressman plans to make higher education more affordable by reducing the costs of student loans, and giving more grants to low-income students. He's also pushed to change the law to enable borrowers to discharge their student loan debt in bankruptcy.

Governor Jay Inlsee speaks at a news conference on his decision to run for president in Seattle on March 1, 2019. Lindsey Wasson / Reuters

Jay Inslee, the Washington governor, has centered his national campaign on climate change, but unveiled a plan for tackling higher education costs in his home state in January. The College Promise grant will offer financial aid for more than 93,000 students by 2021. "A student's financial situation should not prohibit them from pursuing their dreams," Inslee said.

Andrew Yang speaks at a local democratic activist event in Iowa City, Iowa, on March 10, 2019. Scott Morgan / Reuters file

Andrew Yang, the New York entrepreneur, has said he wants to focus on bringing college costs down, in part by "a gradual phase-in of a desired ratio of administrators to students of 1 to 30" instead of the current 1 to 21. He noted that ratio was 1 to 50 in the 1970s. He also wants to require universities with endowments of over $30 billion to contribute 1 percent of their total endowment to establish a new university in Ohio.

Miramar Mayor Wayne Messam poses for a portrait, in Miramar, Florida on March 27, 2019. Brynn Anderson / AP

Mayor Wayne Messam, of Miramar, Florida, who announced he was running for president this week, says he will push for "national student loan forgiveness." "It is time for the federal government to cancel all federal and private student loans," he said in prepared remarks for his campaign launch speech Saturday. He proposes having the government take over responsibility for the loans, which he'd pay off in part by repealing the Trump tax cuts.