President Trump's latest health-care trial balloon was walked back almost as quickly as it was floated. Amid the administration's latest legal challenges to ObamaCare, there was talk of a new working group among Senate Republicans to achieve the goal that eluded them back when they controlled both houses of Congress: to come up with a replacement plan for the law they'd repeal.

April Fool's! Trump soon announced that Republicans wouldn't vote on any ObamaCare alternative until after the 2020 elections. Politico reported he did so "after an aggressive lobbying effort by Senate Republicans, who warned in a series of phone calls that he risked driving his party off an electoral cliff by forcing Republicans to take ownership of the health-care issue." CNN described the state of play as follows: "White House, Congress point fingers over nonexistent health-care plan."

Fake news, the president cried. "I was never planning a vote prior to the 2020 Election on the wonderful HealthCare package that some very talented people are now developing for me & the Republican Party," Trump tweeted. "It will be on full display during the Election as a much better & less expensive alternative to ObamaCare."

What isn't fake is that Republicans are struggling to come up with an alternative to ObamaCare that could actually become law. Trump is hardly atypical when it comes to promising "terrific" care that controls cost without jeopardizing people's coverage. The devil is in the details. Republicans have up until now mostly opposed Democrats' plans, as when they defeated Hillary Clinton's proposal in 1993-94, or offered pale imitations of them, such as RomneyCare or the deficit-funded Medicare prescription drug benefit.

Initially, this worked for them in the fight against ObamaCare. Former President Barack Obama's promise that everyone could keep their doctors and plans if they liked them was simplistic, even false. ObamaCare proved disruptive to many Americans' existing health-care arrangements and that is never popular.

But when Republicans came to power in 2017, suddenly their push to repeal ObamaCare without any consensus on its replacement was the health-care disruptor. Voters didn't believe the Republicans' promises that their plans would protect people with pre-existing conditions, not even in reddish states. This came back to haunt the GOP in the midterm elections, as ObamaCare polled relatively well for the first time since its enactment.

Democrats learned something from ObamaCare's political rollercoaster ride: It was the law's costly private insurance component that was least popular while beneficiaries liked its Medicaid expansion, despite questions about the government health-care program's efficacy. So many Democrats concluded they should fix ObamaCare's problems by expanding an even more popular government program, Medicare, beyond senior citizens.

Here the Democrats may be handing Republicans a health-care lifeline, if the president and his party will seize it. The most ambitious "Medicare-for-all" proposals would alter or nullify existing private health insurance plans. That would make the Democrats health-care disruptors once again, a politically precarious place to be. Folded into a larger critique of Democratic "socialism," that could make some voters feel it isn't just Trump who might take away their health care.

That won't be a permanent solution, of course, anymore than defeating HillaryCare or campaigning against ObamaCare was. At some point, the problems with our medical system will be handled either with more government or better functioning markets. Democrats have shown confidence in their vision while Republicans can barely explain theirs. That suggests if the GOP keeps punting on this issue, it will keep being dealt with on Democratic terms.

In the meantime, however, the Democrats' Medicare plans will likely look like a confirmation of the old quip by conservative humorist P.J. O'Rourke: "If you think health care is expensive now, wait until you see what it costs when it's free." Single-payer systems have worked well enough in other countries, but they're not without their own costs and they have never tried to cut health-care spending from the United States' current astronomical levels.

Even Medicare for all will be hard to beat. It, after all, is something while the Republicans have nothing. Democrats will likely present it as an option to buy into government health care. But they have always run into trouble when they have threatened private insurance, making Republican defenses of the status quo more palatable. But Trump is right they can't run on the status quo forever. If they win this latest fight, they had better figure out what they are for because they may not get another chance.