President Trump floated a new idea on Friday morning: What if the Senate votes to repeal Obamacare today and then works to replace it later?

The idea is apparently coming from Sen. Rand Paul (R-Ky.), who called it a “breakthrough” while detailing it Thursday. “What about dividing the bill in two? Do the repeal, which no Democrat will vote for — repeal the taxes, repeal the regulations — and do a fix to Medicaid that helps to pay for everything,” Paul said. “No Democrats will vote for anything good like that. But Democrats will always vote for spending.” Sen. Ben Sasse (R-Neb.) is also onboard.

The good news for Republicans is that this approach may be more popular than the one they're employing right now. The bad news is it's still hugely unpopular and would be a political gamble on a scale we have rarely seen.

Poll: Senate health-care bill is deeply unpopular (Peter Stevenson/The Washington Post)

The Kaiser Family Foundation polled this very approach back in March, and found only 19 percent of Americans favored repealing Obamacare first and then working to replace it. That's at least higher than the 12-17 percent of Americans who like the Senate health-care bill. But another 75 percent either didn't want it repealed (51 percent) or preferred to hold off on repealing until a replacement is crafted (24 percent).

Quinnipiac University also took a run at this question in March. It asked, “If Congress decides to repeal Obamacare, do you think that Congress should repeal Obamacare as soon as possible even if they have not decided on a plan to replace it, or should they wait to repeal Obamacare until they have a plan to replace it?”

Just 10 percent of people chose “as soon as possible,” while 87 percent (!) said “wait for a replacement.”

These polls may not be perfect illustrations of what Trump and Paul are proposing; Paul's idea seems to be that the plan to replace Obamacare would be worked out beforehand and then simply voted on separately, after repeal, and Sasse has floated a one-year delay on Obamacare shutting down. But the practical implication would be pretty similar: The law would be repealed without a clear replacement in-hand. And the gambit would be at the mercy of whatever happened thereafter.

The logic makes some sense, in the abstract. If Democrats are confronted with Obamacare being ripped out, root and branch, would they really not work with Republicans to restore funding to things like Medicaid?

The problem is that legislating health care, as we've found out, is a hugely messy process. Any replacement of funding would be subject to debate and would face an uncertain future. Democrats might hold out for more Medicaid funding. Republicans might hold out for less Medicaid funding or hold the line on something like cutting off Planned Parenthood. The GOP would essentially be gambling that Congress would have to pass something, thereby absolving them of whatever harmful effects might come from cutting off the Affordable Care Act in one fell swoop.

But we've been down this road before, to some degree, and the lesson is clear: Never underestimate Congress's ability to gridlock itself. Remember the sequester that was supposed to be so bad that it would force Republicans and Democrats to come together to work out a budget? If they didn't, then big, automatic spending cuts would be instituted! And that's exactly what happened.

The GOP also attempted to force Democrats' hands during the 2013 shutdown, when some on the right reasoned that Democrats would have to pass a government funding bill that defunded Obamacare because they couldn't risk a shutdown. But the shutdown happened, and it was blamed on Republicans.

Put plainly, this would be a huge risk, and it's a risk that the American people overwhelmingly oppose. It may well be the best available option for passing something, but that doesn't make it the best move, either politically or for the country's health-care system.

It would be such a risk, in fact, that I'm doubtful Senate Republicans could even assemble 50 votes to repeal it in the first place — which would render the rest of this pretty moot.