Former President Barack Obama took to Facebook on Thursday to make the case for his signature health care law as Republican leadership in the Senate unveiled its plan to repeal and replace Obamacare.

"The Senate bill, unveiled today, is not a health care bill," he wrote in a Facebook post blasting the legislation that repeals the Affordable Care Act. "It's a massive transfer of wealth from middle-class and poor families to the richest people in America."

READ MORE: Senate Republicans unveil Obamacare replacement bill after months of closed-door crafting

"It hands enormous tax cuts to the rich and to the drug and insurance industries, paid for by cutting health care for everybody else," he added. "Those with private insurance will experience higher premiums and higher deductibles, with lower tax credits to help working families cover the costs, even as their plans might no longer cover pregnancy, mental health care, or expensive prescriptions."

He also complained about changes being made to the way pre-existing conditions are qualified under the new legislation, claiming that "discrimination" could become the norm again and that millions of families could "lose coverage entirely."

See the protests that erupted after the bill was revealed Thursday:

11 PHOTOS Protesters removed from outside Sen. Mitch McConnell's office See Gallery Protesters removed from outside Sen. Mitch McConnell's office Huge protest inside and outside of Senate Majority Leader Mitch Mcconnell's office happening right now. https://t.co/Iu9wet6cXx Capitol Police are physically removing protesters who are staging a "die-in" in front of McConnell's office https://t.co/8BU0dW63VI Tense situation outside McConnell's Russell office as protesters gather. Capitol Police blocking off hallway https://t.co/48H3KUipfK Capitol police are dragging people away from Mcconnell's office. https://t.co/ldvakYdvl4 Blood on the floor outside of Leader Mcconnell's office as protestors are physically being removed. https://t.co/z4gVd9t1qe Amid protests outside McConnell's office after release of Senate health bill, security begins dragging people away.… https://t.co/EOETbCPuvG Protest outside of McConnell's office after release of Senate healthcare bill https://t.co/FfALhh52Rd A protest has just begun outside Mitch McConnell's office. Demonstrators say health care cuts could mean life or de… https://t.co/NeyiO7Gu8M Protesters chanting "no cuts to Medicaid" outside McConnell's office. Capitol Police blocked the hallway & proteste… https://t.co/Ab7lsCcfWP More from the scene https://t.co/9lvwuYgb5t Paramedics are now here https://t.co/7PixkfXedj Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

"Simply put, if there's a chance you might get sick, get old, or start a family – this bill will do you harm. And small tweaks over the course of the next couple weeks, under the guise of making these bills easier to stomach, cannot change the fundamental meanness at the core of this legislation," he wrote.

His open plea for Republican in the U.S. Senate to reject the bill is the president's most direct political appeal since he left the White House five months ago.

READ MORE: Capitol Police forcibly remove health care protesters outside Mitch McConnell's office

President Donald Trump had been somewhat critical of the House version of the repeal and replace legislation that passed last month, calling it "mean" in a recent meeting. The Senate legislation proposes repealing a 3.8 percent net investment income tax on high earners, which affects high-income Americans and was imposed to help pay for Obamacare.

The Senate bill maintains much of the structure of the House bill, but differs in several key ways.

It would phase out Obamacare's expansion of the Medicaid program for the poor and disabled over three years, from 2021 to 2024, and then enact deeper cuts in the program than the House version beginning in 2025. It would also allow states to add work requirements for some Medicaid enrollees. The legislation also reshapes subsidies to low-income people for private insurance.

RELATED: See Obama's travels since leaving the White House

36 PHOTOS Barack Obama post-presidency See Gallery Barack Obama post-presidency Canada's Prime Minister Justin Trudeau speaks with former United States President Barack Obama at a restaurant during Obama's visit to address the Montreal Chamber of Commerce, in Montreal, Quebec, Canada June 5, 2017. Picture taken June 5, 2017. Prime Minister's Office/Handout via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. EDITORIAL USE ONLY. TPX IMAGES OF THE DAY Former U.S. President Barack Obama waves after speaking at the Global Food Innovation Summit in Milan, Italy May 9, 2017. REUTERS/Alessandro Garofalo TPX IMAGES OF THE DAY Britain's Prince Harry (R) and former U.S. President Barack Obama watch a wheelchair basketball event during the Invictus Games in Toronto, Ontario, Canada September 29, 2017. REUTERS/Mark Blinch Former U.S. President Barack Obama gestures as he delivers his keynote speech to the Montreal Chamber of Commerce at the Palais de Congres in Montreal, Quebec, Canada June 6, 2017. REUTERS/Dario Ayala Sep 28, 2017; Jersey City, NJ, USA; Former U.S. Presidents (from Left) Barack Obama and George W. Bush and Bill Clinton smile during the first round foursomes match of The President's Cup golf tournament at Liberty National Golf Course. Mandatory Credit: Bill Streicher-USA TODAY Sports Former U.S. President Barack Obama speaks at the Bill & Melinda Gates Foundation Goalkeepers event in New York, U.S., September 20, 2017. REUTERS/Elizabeth Shafiroff Former U.S. President Barack Obama and British businessman Richard Branson sit on a boat during Obama's holiday on Branson's Moskito island, in the British Virgin Islands, in a picture handed out by Virgin on February 7, 2017. Jack Brockway/Virgin Handout via REUTERS FOR EDITORIAL USE ONLY German Chancellor Angela Merkel and former U.S. President Barack Obama attend a discussion at the German Protestant Kirchentag in front of the Brandenburg Gate in Berlin, Germany, May 25, 2017. REUTERS/Axel Schmidt TPX IMAGES OF THE DAY Argentina's President Mauricio Macri and former U.S. President Barack Obama walk at a golf course in Bella Vista, on the outskirts of Buenos Aires, Argentina October 7, 2017. Argentine Presidency/Handout via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. Former U.S. President Barack Obama stands onstage after receiving the 2017 Profile in Courage Award during a ceremony at the John F. Kennedy Library in Boston, Massachusetts, U.S., May 7, 2017. REUTERS/Brian Snyder Former president Barack Obama and his wife Michelle board Special Air Mission 28000, a Boeing 747 which serves as Air Force One, at Joint Base Andrews, Maryland, U.S. January 20, 2017. REUTERS/Brendan McDermid Caroline Kennedy presents the 2017 Profile in Courage Award to former U.S. President Barack Obama, as former first lady Michelle Obama looks on, during a ceremony at the John F. Kennedy Library in Boston, Massachusetts, U.S., May 7, 2017. REUTERS/Brian Snyder TPX IMAGES OF THE DAY Former U.S. President Barack Obama greets supporters after speaking at a community event on the Obama Presidential Centre at the South Shore Cultural Centre in Chicago, Illinois, U.S., May 3, 2017. REUTERS/Kamil Krzaczynski Former U.S. President Barack Obama (C) meets with youth leaders Kelsey McClear (L) from Loyola University, Ramuel Figueroa (2nd L) from Roosevelt University, pharmacist Dr. Tiffany Brown (3rd L), Max Freedman (3rd R) from University of Chicago, Harish Patel (2ndL) from New America Foundation and Ayanna Watkins (R) from Kenwood High School at the Logan Center for the Arts at the University of Chicago to discuss strategies for community organization and civic engagement in Chicago, Illinois, U.S., April 24, 2017. REUTERS/Kamil Krzaczynski Former U.S. President Barack Obama speaks during a meeting with youth leaders at the Logan Center for the Arts at the University of Chicago to discuss strategies for community organization and civic engagement in Chicago, Illinois, U.S., April 24, 2017. REUTERS/Kamil Krzaczynski Former president Barack Obama reacts after addressing staff and guests before boarding Special Air Mission 28000, a Boeing 747 which serves as Air Force One, at Joint Base Andrews, Maryland, U.S. January 20, 2017. REUTERS/Brendan McDermid U.S. President Donald Trump (L) greets former President Barack Obama after being sworn in as the 45th president of the United States on the West front of the U.S. Capitol in Washington, U.S., January 20, 2017. REUTERS/Lucy Nicholson Former president Barack Obama rallies with New Jersey Democratic Gubernatorial candidate Jim Murphy in Newark, New Jersey, U.S. October 19, 2017. REUTERS/Mark Makela U.S. President Barack Obama dances with Jill Biden (2nd L) as Britain's Prince Harry (R) and former U.S. Vice President Joe Biden (L) watch a wheelchair basketball event at the Invictus Games in Toronto, Ontario, Canada, September 29, 2017. REUTERS/Mark Blinch Former U.S. President Barack Obama accompanied by Melinda and Bill Gates speaks at the Bill & Melinda Gates Foundation Goalkeepers event in New York, U.S., September 20, 2017. REUTERS/Elizabeth Shafiroff Former U.S. President Barack Obama visits Prambanan Temple in Sleman, Yogyakarta, Indonesia June 29, 2017. REUTERS/Pius Erlangga Former United States President Barack Obama (2nd L), his wife Michelle (3rd L) along with his daughters Sasha (C) and Malia (2nd R) go rafting while on holiday in Bongkasa Village, Badung Regency, Bali, Indonesia June 26, 2017 in this photo taken by Antara Foto. Antara Foto/Wira Suryantala/ via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. MANDATORY CREDIT. INDONESIA OUT. NO COMMERCIAL OR EDITORIAL SALES IN INDONESIA. TPX IMAGES OF THE DAY Former U.S. President Barack Obama (L) and Indonesian President Joko Widodo are seen during their meeting at the Botanical Garden near the presidential palace in Bogor, Indonesia June 30, 2017. REUTERS/Adi Weda/Pool Former United States' President Barack Obama, smiles as he delivers a speech during the Green Economy Summit 2017 in Cordoba province some 740 kilometres Northwestern Buenos Aires, on October 6, 2017. The global fight for clean energy rests with businesses and ordinary people as governments lag behind, experts told an environmental conference in Argentina Friday ahead of a keynote speech by former US president Barack Obama. / AFP PHOTO / Pablo Gasparini (Photo credit should read PABLO GASPARINI/AFP/Getty Images) TORONTO, ON - SEPTEMBER 29: Prince Harry, former U.S. President Barack Obama, former Vice President of the U.S. Joe Biden and former second lady of the U.S. Jill Biden pose with competitors from Team USA on day 7 of the Invictus Games 2017 on September 29, 2017 in Toronto, Canada. (Photo by Chris Jackson/Getty Images for the Invictus Games Foundation ) TORONTO, ON - SEPTEMBER 29: Former U.S. President Barack Obama greets members of the public on day 7 of the Invictus Games 2017 on September 29, 2017 in Toronto, Canada. (Photo by Chris Jackson/Getty Images for the Invictus Games Foundation ) JERSEY CITY, NJ - SEPTEMBER 28: Captain's Assistant Tiger Woods of the American Team talks to former President of the United States Barack Obama at the first tee during the first round of the Presidents Cup at Liberty National Golf Club on September 28, 2017 in Jersey City, New Jersey. (Photo by Shelley Lipton/Icon Sportswire via Getty Images) Former U.S. President Barack Obama and former first lady Michelle Obama react to the crowd during an unveiling ceremony for their portraits at the Smithsonian's National Portrait Gallery in Washington, U.S., February 12, 2018. REUTERS/Jim Bourg Former U.S. President Barack Obama speaks during an unveiling ceremony for portraits of himself and former First Lady Michelle Obama at the Smithsonian's National Portrait Gallery in Washington, U.S., February 12, 2018. REUTERS/Jim Bourg Former U.S. President Barack Obama speaks during a Leadership Summit in Delhi, India, December 1, 2017. REUTERS/Cathal McNaughton Former U.S. president Barack Obama speaks at a conference during his first visit to France since he left the White House, Paris, France December 2, 2017. The session, organized by an association called "Les Napoleons" is hosted by Orange CEO Stephane Richard. REUTERS/Benoit Tessier Former U.S. President Barack Obama reacts during a Leadership Summit in Delhi, India, December 1, 2017. REUTERS/Cathal McNaughton Former U.S. President Barack Obama listens to his wife Michelle Obama (unseen) as she speaks during the second day of the first Obama Foundation Summit in Chicago, Illinois, U.S. November 1, 2017. REUTERS/Kamil Krzaczynski Former U.S. President Barack Obama campaigns in support of Virginia Lieutenant Governor Ralph Northam, Democratic candidate for governor, at a rally with supporters in Richmond, Virginia, U.S. October 19, 2017. REUTERS/Jonathan Ernst Former President Barack Obama greets supporters after joining New Jersey Democratic Gubernatorial candidate Jim Murphy at a rally in Newark, New Jersey U.S. October 19, 2017. REUTERS/Mark Makela Former U.S. President Barack Obama campaigns in support of Virginia Lieutenant Governor Ralph Northam, Democratic candidate for governor, at a rally with supporters in Richmond, Virginia, U.S. October 19, 2017. REUTERS/Jonathan Ernst Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

Read the full text of President Obama's below:

Our politics are divided. They have been for a long time. And while I know that division makes it difficult to listen to Americans with whom we disagree, that's what we need to do today.

I recognize that repealing and replacing the Affordable Care Act has become a core tenet of the Republican Party. Still, I hope that our Senators, many of whom I know well, step back and measure what's really at stake, and consider that the rationale for action, on health care or any other issue, must be something more than simply undoing something that Democrats did.

We didn't fight for the Affordable Care Act for more than a year in the public square for any personal or political gain – we fought for it because we knew it would save lives, prevent financial misery, and ultimately set this country we love on a better, healthier course.

Nor did we fight for it alone. Thousands upon thousands of Americans, including Republicans, threw themselves into that collective effort, not for political reasons, but for intensely personal ones – a sick child, a parent lost to cancer, the memory of medical bills that threatened to derail their dreams.

And you made a difference. For the first time, more than ninety percent of Americans know the security of health insurance. Health care costs, while still rising, have been rising at the slowest pace in fifty years. Women can't be charged more for their insurance, young adults can stay on their parents' plan until they turn 26, contraceptive care and preventive care are now free. Paying more, or being denied insurance altogether due to a preexisting condition – we made that a thing of the past.

We did these things together. So many of you made that change possible.

At the same time, I was careful to say again and again that while the Affordable Care Act represented a significant step forward for America, it was not perfect, nor could it be the end of our efforts – and that if Republicans could put together a plan that is demonstrably better than the improvements we made to our health care system, that covers as many people at less cost, I would gladly and publicly support it.

That remains true. So I still hope that there are enough Republicans in Congress who remember that public service is not about sport or notching a political win, that there's a reason we all chose to serve in the first place, and that hopefully, it's to make people's lives better, not worse.

But right now, after eight years, the legislation rushed through the House and the Senate without public hearings or debate would do the opposite. It would raise costs, reduce coverage, roll back protections, and ruin Medicaid as we know it. That's not my opinion, but rather the conclusion of all objective analyses, from the nonpartisan Congressional Budget Office, which found that 23 million Americans would lose insurance, to America's doctors, nurses, and hospitals on the front lines of our health care system.

The Senate bill, unveiled today, is not a health care bill. It's a massive transfer of wealth from middle-class and poor families to the richest people in America. It hands enormous tax cuts to the rich and to the drug and insurance industries, paid for by cutting health care for everybody else. Those with private insurance will experience higher premiums and higher deductibles, with lower tax credits to help working families cover the costs, even as their plans might no longer cover pregnancy, mental health care, or expensive prescriptions. Discrimination based on pre-existing conditions could become the norm again. Millions of families will lose coverage entirely.

Simply put, if there's a chance you might get sick, get old, or start a family – this bill will do you harm. And small tweaks over the course of the next couple weeks, under the guise of making these bills easier to stomach, cannot change the fundamental meanness at the core of this legislation.

I hope our Senators ask themselves – what will happen to the Americans grappling with opioid addiction who suddenly lose their coverage? What will happen to pregnant mothers, children with disabilities, poor adults and seniors who need long-term care once they can no longer count on Medicaid? What will happen if you have a medical emergency when insurance companies are once again allowed to exclude the benefits you need, send you unlimited bills, or set unaffordable deductibles? What impossible choices will working parents be forced to make if their child's cancer treatment costs them more than their life savings?

To put the American people through that pain – while giving billionaires and corporations a massive tax cut in return – that's tough to fathom. But it's what's at stake right now. So it remains my fervent hope that we step back and try to deliver on what the American people need.

That might take some time and compromise between Democrats and Republicans. But I believe that's what people want to see. I believe it would demonstrate the kind of leadership that appeals to Americans across party lines. And I believe that it's possible – if you are willing to make a difference again. If you're willing to call your members of Congress. If you are willing to visit their offices. If you are willing to speak out, let them and the country know, in very real terms, what this means for you and your family.

After all, this debate has always been about something bigger than politics. It's about the character of our country – who we are, and who we aspire to be. And that's always worth fighting for.

(Reuters contributed to this report)