The warnings were dire.

The American Medical Association was so opposed that it hired then-actor and future-president Ronald Reagan to voice its concerns. And in a series of ads, paid speeches and a 1961 record distributed by the AMA, Reagan made a case.

If Medicare became a reality, the argument went, this moment would later be understood as the beginning of socialism in the United States. And, Reagan said in no uncertain terms, Medicare would also someday be understood as the end of things Americans hold dear, including, well, freedom. (You can listen for yourself if you click on the video below. The heart of Reagan's argument begins at 5:24.)

That should sound at least a little familiar to anyone who lived through the Clintons' disastrous attempt to build a national health-care program and anyone awake for the last few years of disagreement about Obamacare, a.k.a. the Affordable Care Act.

This is language so powerful that it helped give birth to a very profitable and now-omnipresent industry -- political communications -- in the 1940s. But, despite the potency of Reagan's 1961 message, President Lyndon B. Johnson signed the Medicare bill 50 years ago Thursday.

And people who have studied the Medicare program closely say that it's what happened in the 365 days after -- once the bureaucrats got to work -- that changed the country. Scary as that might sound to people who oppose public health-care programs and those who worry about mushrooming costs and enrollment, researchers have credited Medicare with contributing to longer life spans and helping to reduce senior-citizen poverty.

But what's much less widely known is this: Medicare helped to integrate the nation's hospitals -- rapidly.

First a little history

President Harry S. Truman tried and failed. President John F. Kennedy did the same. He had compelling and shrewd opponents; in addition to Reagan, the American Medical Association's membership (which was of course overwhelmingly white and male) dispatched their wives, often the doyennes of society, to host local teas and talk up the risk of public health care, according to David Barton Smith, a professor emeritus in health-care management at Temple University.

According to Smith, American doctors in the 1960s were seen as the rightful owners of the final word on national health-care policy.

But after a landslide election in 1964 and passing bills like the Civil Rights Act and the Voting Rights Act, Johnson got the Medicare bill through Congress.

The Brown v. Board of Education decision had already ruled the "separate but equal" doctrine unconstitutional in 1954. And the Civil Rights Act, passed in 1964, mandated not only an end to segregation in public facilities but also private ones that were open to the public. Still, battles over basic constitutionally guaranteed rights persisted.

In most places -- particularly the South -- hospitals remained very strictly segregated, Smith said. There was white hospital in most cities in which federal dollars had often been used to build or maintain modern facilities with modern technology. In communities where non-whites were (relatively) lucky, there were black facilities that were generally not like that. Black doctors were not granted privileges to practice, and their non-white patients were routinely turned away, sometimes even in cases of life-threatening emergencies.

That's just the way health care was done

Bogged down with securing black voting rights and access to public and private facilities, the Johnson administration left implementation of Medicare to the nation's health officials, Smith told me. Instructions: keep things quiet. And avoid a backlash. The agency sent out letters in March 1966 telling hospitals what they would have to do to become eligible for Medicare dollars and maintain access to an existing program that provided federal matching dollars for hospital facilities.

Then, a team of just five investigators worked with volunteers -- mostly black health-care workers and civil rights activists around the country -- to find the hospitals that weren't in compliance. By July 1966, when the Medicare program began, nearly 2,000 hospitals had integrated to remain connected to the federal spigot, Smith told me.

"Sometimes we forget the real golden rule," said Smith, who is working on a book about Medicare and civil rights. "He who has the gold makes the rules."

In his 2010 book, "The Heart of Power," author David Blumenthal describes things slightly differently. (Blumenthal served as the Obama administration's health information technology coordinator.) Johnson may have wanted it done quietly, but he was determined to use Medicaid as a vehicle for what he saw as important social change.

When Johnson learned that half of the hospitals in 12 Southern states were either actively resisting integration or moving slowly in hopes that the administration would cave on this requirement, he put his vice president to work calling mayors. And Johnson's determination eventually became so clear that only about a dozen hold-out hospitals remained three months after Medicare began.

Still, it's more than fair to say that Medicare didn't solve the entire problem with race and access to health care. Some private hospitals continued to resist integration. Even the public and private hospitals that complied early on found some workarounds, Smith told me. Within a few years, most hospitals had gotten rid of multi-bed hospital wards that put patients in very close contact. The once-small collection of double-occupancy and private rooms became the new norm -- the only option.

That transformation continues

The United States has about half the number of beds of any developed country, per capita, and the shortest hospital stays -- in part because of a shortage of beds created by the move away from multi-bed wards, Smith said. At the same time, all that out-patient care isn't containing costs.

And everything that happened as a result of Medicare and the pretty-substantial role of private health insurance companies still wasn't enough to keep the s-word and related claims about health-care rationing from coming up in debates about the Affordable Care Act, Robert Berenson, a physician who oversaw Medicare payments policy for the Clinton administration, told me.

Berenson is a health-care finance guy who is also a fellow at the left-leaning Urban Institute, researching the competition and consolidation in the health-care industry. And his read on Medicare is this:

The program is far healthier than a lot of the political chatter makes the American public believe. There are challenges, but its real fiscal problems stem from something no one can change.

"I say this as a person who was born within two months of Bill Clinton, George Bush and Donald Trump," Brenson said. "We are the baby-boom generation and we are the problem. There are just lot more people who can enroll in Medicare and a lot more people who are going to get old and are going to get sick. That is the issue."