Former President Barack Obama slammed the Senate GOP's health care proposal released Thursday as "not a health care bill," but rather, a "transfer of wealth from middle-class and poor families to the richest people in America."

Obama said he hopes the proposed "discussion draft" of the Senate's health care bill that repeals key components of his signature Affordable Care Act aims at more than "simply undoing something that Democrats did." The former president made the statement hours after the Senate unveiled its formerly secret proposal for the first time.

"I recognize that repealing and replacing the Affordable Care Act has become a core tenet of the Republican Party," Obama said in a Facebook message. "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."

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"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," Obama continued.

The former president said the House and Senate proposals -- the House passed its own health care bill last month -- would raise costs, roll back coverage protections, and "ruin Medicaid as we know it." The Congressional Budget Office found the House bill would lead to 23 million fewer Americans having insurance by 2026.

"The Senate bill, unveiled today, is not a health care bill," Obama said. "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."

"Simply put, if there's a chance you might get sick, get old, or start a family – this bill will do you harm," Obama added later. "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."

The Senate health care proposal is already in jeopardy. Four GOP senators have expressed their opposition to the legislation in its current form, which would eliminate Republicans' chance of passing the bill as-is. Senate Majority Leader Mitch McConnell, R-Kentucky, has said he wants a vote on the bill before the Senate recesses for the July 4 holiday.