ST. CLAIRSVILLE, Ohio — Shortly after he finished his rib-eye steak and baked potato on Saturday night, Sen. Bernie Sanders (I-VT) was interrupted by his Outback Steakhouse waitress. “I just wanted to thank you for all you’ve done,” she said. “All of us fought over who would get to take this table.”

Sanders was in the middle of doing something notable, and perhaps a bit awkward. He was on a campaign-style trip through western Pennsylvania, Ohio, and West Virginia, well before anyone might reasonably be campaigning for the next presidential election. And at each stop, he was rallying to save Obamacare, a health law he criticized relentlessly in his rise through the Democratic primaries in 2016, but which now hangs in the balance in the Senate.

Sanders was trying to find a way to fuse his calls for a single-payer health care system with a plea to save the system he wants it to replace.

His bridge was Medicaid. In his speeches, Sanders cast the Republican health care bill now pending in the Senate as cutting Medicaid for the poor to pass tax cuts for the rich rather than as a way to repeal many of the controversial and complicated policies embedded in the Affordable Care Act.

If Democrats can make this battle a referendum on Medicaid rather than one on Obamacare, Sanders seemed to suggest, they’ll have a shot at saving both — and building toward a single-payer future.

In his speeches, Sanders focused overwhelmingly on the impact of Medicaid cuts

They showed up by the thousands. About 1,700 people in Pittsburgh, 2,700 in Columbus, around 600 in Charleston — all came to see Sanders’s health care rallies as if they were being held in the heat of a presidential campaign.

David Bowie’s “Starman” played on a seemingly endless loop at all of the events. The crowds overflowed the auditoriums, as attendees waved banners reading “Medicare-for-All,” and the big screen overhead displayed charts from the Congressional Budget Office. Vendors hawked “Bernie 2020” pins. One volunteer in Columbus reported several hundred people began showing up at close to 7:30 am.

But amid the festival-like atmosphere, Sanders had a grim message for the audience: Senate Republicans are trying to kill children, the poor, and the disabled, he said, by taking away their Medicaid, in order to subsidize enormous tax cuts for the 1 percent.

“This bill calls for massive cuts to Medicaid ... at the same time, this legislation would allow the 400 highest-income taxpayers, most of them billionaires, to receive $33 billion in tax cuts,” Sanders thundered in Ohio.

I went to all three rallies, and the throughline of Medicaid was unmistakable.

Here was Sanders at the Pittsburgh Convention Center, near where the city’s three rivers meet: “What every person in Pennsylvania should understand is that Medicaid now pays for over two-thirds of all nursing home care. What happens to the 50,000 seniors and persons with disabilities in Pennsylvania who have their nursing home coverage paid for by Medicaid today?”

And at Columbus’s Express Live center: “What happens if they cut Medicaid? If you are a child with a severe disability, you will no longer get the health care you need. An estimated 11 million children, or 15 percent of all kids, have special health care needs. ... Today, Medicaid and CHIP cover 5 million kids, or 44 percent of those children, providing them with coverage so they can live with dignity and security. If Medicaid is cut, is slashed, children with special health care needs could be left to fend for themselves. I want you to think about that: Children with serious health problems would be forced to fend for themselves.”

And at the municipal auditorium in Charleston: With the Medicaid cuts, “2,700 people here in West Virginia won’t get the treatment they desperately need” to address their opioid addiction.

In just three speeches, Sanders managed to mention the word “Medicaid” upward of 40 times. He did not mention either “Obamacare” or “the Affordable Care Act” more than a couple of times in each state, and when he did, it was often to recognize the law’s deficiencies.

"We know what massive Medicaid cuts will do," he said in West Virginia, adding: “And we do not hurt the children, the elderly, veterans, the poor in order to give massive tax breaks to billionaires who do not need it."

Republicans are trying to make this about repealing and replacing Obamacare

Senate Republicans have until very recently shied away from talking about the Medicaid portions of their health bill — and when they have discussed them, they have often downplayed any potential harm from reduced funding for the program.

“The Senate bill will codify and make permanent the Medicaid expansion, and in fact we'll have the federal government pay the lion’s share of the cost. ... No one loses coverage," Sen. Pat Toomey (R-PA) said Sunday on CBS, in a statement that liberal health care advocates roundly denounced as a lie. In Colorado on Sunday, meanwhile, Sen. Ben Sasse (R-NE) said the Senate bill is “largely a Medicaid reform package.”

Other Republicans have stressed shortcomings in Obamacare to make the case for fast action on a replacement bill. Earlier this month, Vox’s Tara Golshan, Dylan Scott, and I interviewed eight Republican senators about the bill, which had not yet been finalized. Sen. Ted Cruz (R-TX) talked about “how people are frustrated and angry with Obamacare.” Sen. John Boozman (R-AR) homed in on a situation with “Obamacare that, again, we don’t have a sustainable product.” Sen. Lisa Murkowski (R-AK) talked about “the imperative of why you need to repeal and replace [Obamacare].”

None of them mentioned Medicaid — except, in some cases, to defend it and say that they were worried about serious cuts to it. But unifying them was the need to do away with “Obamacare.” And with good reason: Until a very recent uptick, the law has been unpopular for years, particularly on the Republican side. Critics have identified real problem with the Obamacare exchanges that Republicans have made so much political hay out of criticizing.

By contrast, in a poll last week, Kaiser found that 73 percent of Americans have a favorable view of Medicaid, with just 19 percent saying they have an unfavorable view. Even with its recent rise in popularity, “Obamacare” has a favorable-unfavorable rating of 51 to 41 percent, the poll found.

So it makes sense that Republicans would want to cast their desire to reform Medicaid within their project to reform “Obamacare.”

As Vox’s Sarah Kliff explains, the Senate bill would sunset the Medicaid expansion passed under Obamacare, almost certainly resulting in millions fewer gaining coverage. It would also chain the federal government’s Medicaid spending to a stricter measure of inflation, thus sharply reducing how much gets spent. Neither of those proposals has been the focal point of the Republican critique of the American health care system.

“Republicans campaigned against the conservative parts of Obamacare, and then they’re going to turn around and take away the parts that expanded the social safety net, going beyond even repealing Obamacare,” said Ben Wikler, legislative director of MoveOn.org, as he rode in a Zipcar from Pittsburgh to Columbus on Saturday night.

These dynamics help explain Sanders’s pitch to the crowds over the weekend. His rhetoric contained degrees of ambivalence, deflection, and — above all — avoidance about Obama’s signature achievement. “Everyone here knows — it’s no big secret — that the Affordable Care Act is far from perfect,” he said in Ohio. “Our job now is to improve it, not destroy it.”

It looked like his audience was hearing the message. Or perhaps they had arrived with it already internalized.

People at Sanders rallies are much more fired up about Medicaid than the ACA

Tally Mainland, 41, teaches poor students in Marion County, West Virginia. She appeared early at the municipal auditorium on Sunday to see Sanders.

"All the children I teach are low-income — I don't think we have any kid whose parents don't have it,” she said.

Added her friend, 68-year-old Gina Stanley: "Half of the babies in this state are born with Medicaid.”

By contrast, many event attendees were ambivalent about “Obamacare,” and reflected Sanders’s call to move to a single-payer or “Medicare-for-all” health care system. Shirley Inman, 73, who wore a United Mine Workers of America shirt to the rally, said she had serious reservations about Obamacare.

“It was a small step forward,” she said, “but I really think we should do much better. It’s a shame that you get fined if you can’t afford insurance. We should be able to do much better than that.”

The reactions probably shouldn’t surprise anyone, given the makeup of Sanders’s crowds. The Medicaid expansion is the most left-leaning part of the ACA, and it’s also the most popular.

“In this region, it's critical because that's what a lot of people’s insurance is. It endangers the lives of my neighbors and family members; it's really personal,” said Sean McCallister, 18, in West Virginia.

Renita Golson, 28, said that her boyfriend and family would risk losing all of their money if Medicaid got defunded in a meaningful way. “If they take that away,” she said, “we’ll be bankrupt overnight.”