Sen. Kamala Harris, the California Democrat considered a potential 2020 presidential hopeful, aligned herself with the liberal wing of her party this week by endorsing Sen. Bernie Sanders' single-payer health care proposal – multitrillion-dollar price tag and all.

Harris told constituents at a town hall in Oakland that she planned to co-sponsor Sanders’ forthcoming “Medicare for All” bill, explaining that it was “just the right thing to do.”

“It’s not just about what is morally and ethically right, it also makes sense from a fiscal standpoint,” Harris said Wednesday.

Last month, Harris said that she supported the single-payer system as a “concept,” but that lawmakers needed to “work out the details.” Her announcement to co-sponsor Sanders’ bill is the first time she has publicly supported a single-payer plan.

SINGLE-PAYER HEALTH CARE: WHAT IS IT?

Under this European-style health care system, the government is solely responsible for covering health care costs. Sanders, I-Vt., rolled out an earlier version of his proposal during the Democratic presidential primaries in 2016.

At the time, he initially estimated the plan would cost $13.8 trillion over the first 10 years. But according to an analysis by the nonpartisan Urban Institute, the single-payer system would cost the federal government more like $32 trillion over the first decade, requiring an average annual tax increase of $24,000 per household. (That increase would be offset in part by a big reduction in private health care spending, and state/local government spending.)

But a spokeman for Sanders told Fox News on Thursday that the Urban Institute's figure was "not accurate" with respect to the 2017 proposal.

"This bill is substantially different and more detailed than the brief plan released during the campaign," Sanders' spokesman told Fox News.

Sanders' office told Fox News that the bill has yet to be released, but, once it is finalized, they would have a "better sense" of the cost. The bill is expected to be rolled out the second week of September.

“You’re seeing more and more movement toward Medicare for All,” Sanders said this week. “When the people are saying we need health care for everyone, as more and more Americans come on board, it will become politically possible.”

Sanders thanked Harris on Twitter late Wednesday for her support.

“Thank you @KamalaHarris for your support. Let’s make health care a right, not a privilege,” Sanders tweeted.

Another bill, introduced in the House by Rep. John Conyers, D-Mich., would attempt to establish a Medicare for All program to provide Americans with a broad range of health care, including emergency care, primary care, prescription drugs and vision care. That bill currently has 117 cosponsors.

Fox News' Kaitlyn Schallhorn contributed to this report.