John Oliver, the ever-exasperated host of HBO’s fake news show “Last Week Tonight,”tackled the complicated issue of Medicaid expansion Sunday night, excoriating Republican candidates and state lawmakers in Mississippi, Kentucky, and Virginia who’ve refused to expand Medicaid under Obamacare.

Parts of his bit were kind of funny, and if you don’t know much about Obamacare or Medicaid or cooperative federalism or state budgets, the whole thing was hilariously informative. You could just sit back and laugh at Oliver’s jaunty, British-accented jokes about the stupidity of all those Republican rubes down south who want to deny health care to poor people.

After all, reasoned Oliver, what possible reason could there be to oppose the expansion of a program that provides health care to the poor, especially when the federal government is going to pay for the entire cost of expansion for the first three years and 90 percent after that? “I can’t think of anything I would not buy if I only had to pay 10 percent of the price,” jokes Oliver. “Fred Claus on DVD? No, thank you, but yes, I’ll take it. Vince Vaughn is always good for forty-nine cents worth of yuks.” Hahaha. Funny.

But what if you had to pay 10 percent of, say, $5 billion—every year? And the thing you were buying would force childless, non-disabled, working-age adults to enroll in a program that provides the worst health coverage in the country? That’s less funny, which is probably why Oliver didn’t mention it.

Kentucky’s Medicaid Is a Bust

Instead, he goes on to explain that Medicaid expansion has worked “brilliantly” in Kentucky, with the nation’s steepest drop in the number of uninsured. “Only an idiot would try to undo that,” he says. “Which brings me to gubernatorial candidate Matt Bevin.” Hahaha. Get it? Because Bevin was the GOP candidate for governor in Kentucky. On Tuesday he became the second Republican to be elected governor there in 40 years.

What Oliver doesn’t mention, because it’s not worth any yuks and it doesn’t match the White House script he’s following, is that Kentucky’s Medicaid expansion last year enrolled more than twice the number of people the state anticipated, with the predictable result that the expansion is projected to run over budget by $1.8 billion this year.

Something similar is unfolding in every state that has expanded Medicaid. California thought fewer than 800,000 people would enroll. It ended up being 2 million. In Illinois, more adults have already enrolled than the state thought would ever be eligible. In Maryland and Nevada, enrollment is more than double the estimate. In Colorado, it’s triple.

Higher enrollment means higher costs. Washington had to increase its budget by $2.3 billion to deal with costs that blew away projections. In Ohio, Gov. John Kasich’s Medicaid expansion has now cost federal taxpayers more than $5 billion—it was supposed to be less than half that. If spending there continues apace, it’ll cost $4 billion every year to keep Ohio’s Medicaid experiment afloat.

After the federal government drops its funding down to 90 percent of the cost, Ohio residents will have to pay an estimated $5.3 billion from 2019-26 to keep the program going, which could be as much as $20 billion if Congress reduces the federal share to pre-Obamacare levels.

Money from The Magic Sky God

Boring stuff, I know. That must be why Oliver left it out of his act. Or maybe he doesn’t actually know how any of this works. After all, Oliver approvingly showed a clip of Kasich defending Medicaid expansion and remarked, “all Kasich technically did was see a dump truck full of money backing into his driveway and just not say ‘stop,’” as if dump trucks full of money can be dispatched from Washington DC without Americans first filling them up with their tax dollars.

That’s exactly what’s happening. Kasich often says he’s “bringing back Ohio’s federal tax dollars”—a line he’s repeated often on the campaign trail. But as the Congressional Research Service and Congressional Budget Office have repeatedly made clear, that’s not how it works at all. Every state that expands Medicaid costs federal taxpayers more, and those costs are helping to drive increased federal spending, up 5.2 percent this fiscal year. Of that increase, more than 16 percent was for Medicaid expansion, which has caused total federal Medicaid spending to grow from $85 billion to $350 billion in just two years.

I get it. Oliver’s shtick was funny. This is not funny. Too many numbers and cost-benefit trade-offs to consider—just the sort of considerations Oliver didn’t want to provoke in his fans, any more than Obamacare advocates want to provoke in voters.

Sit Right on Down for Electioneering

The timing of the segment was no accident, and Oliver said so at the outset. Mississippi, Virginia, and Kentucky were the three states with elections on Tuesday whose outcome, had Democratic candidates won, likely would have meant Medicaid expansion in some form. But Democrats didn’t win. They lost badly. In Kentucky, as mentioned before, a Tea Party candidate won the governor’s race.

In Virginia, despite Democratic Gov. Terry McAuliffe’s efforts to put his party in control of the state senate so he could pass the same Medicaid expansion scheme the legislature rejected earlier this year, Republicans kept control of the senate.

No doubt these results will confirm to Oliver and his fans that voters in those states are “idiots”—especially voters from poorer counties in east Kentucky that supported Bevin. No doubt Oliver will mock them on future shows. No doubt his audience will relish it.

It’s highly doubtful, though, that any of them will seek out some other source of information about Medicaid expansion or Obamacare. It’s doubtful they will ever hear about it again except maybe on Oliver’s show or Jon Stewart’s new show. Maybe that was not the purpose of the segment. Maybe it had to do with something more than mere entertainment. Seen in that light, maybe it’s not quite so funny after all.

John is the director of the Center for Health Care Policy at the Texas Public Policy Foundation in Austin, Texas. Follow him on Twitter.