When it comes to health reform, Republicans suffer from delusions of disaster. They know, just know, that the Affordable Care Act is doomed to utter failure, so failure is what they see, never mind the facts on the ground.

Thus, on Tuesday, Mitch McConnell, the Senate minority leader, dismissed the push for pay equity as an attempt to “change the subject from the nightmare of Obamacare”; on the same day, the nonpartisan RAND Corporation released a study estimating “a net gain of 9.3 million in the number of American adults with health insurance coverage from September 2013 to mid-March 2014.” Some nightmare. And the overall gain, including children and those who signed up during the late-March enrollment surge, must be considerably larger.

But while Obamacare is looking like anything but a nightmare, there are indeed some nightmarish things happening on the health care front. For it turns out that there’s a startling ugliness of spirit abroad in modern America — and health reform has brought that ugliness out into the open.

Let’s start with the good news about reform, which keeps coming in. First, there was the amazing come-from-behind surge in enrollments. Then there were a series of surveys — from Gallup, the Urban Institute, and RAND — all suggesting large gains in coverage. Taken individually, any one of these indicators might be dismissed as an outlier, but taken together they paint an unmistakable picture of major progress.

But wait: What about all the people who lost their policies thanks to Obamacare? The answer is that this looks more than ever like a relatively small issue hyped by right-wing propaganda. RAND finds that fewer than a million people who previously had individual insurance became uninsured — and many of those transitions, one guesses, had nothing to do with Obamacare. It’s worth noting that, so far, not one of the supposed horror stories touted in Koch-backed anti-reform advertisements has stood up to scrutiny, suggesting that real horror stories are rare.

It will be months before we have a full picture, but it’s clear that the number of uninsured Americans has already dropped significantly — not least in Mr. McConnell’s home state. It appears that around 40 percent of Kentucky’s uninsured population has already gained coverage, and we can expect a lot more people to sign up next year.

Republicans clearly have no idea how to respond to these developments. They can’t offer any real alternative to Obamacare, because you can’t achieve the good stuff in the Affordable Care Act, like coverage for people with pre-existing medical conditions, without also including the stuff they hate, the requirement that everyone buy insurance and the subsidies that make that requirement possible. Their political strategy has been to talk vaguely about replacing reform while waiting for its inevitable collapse. And what if reform doesn’t collapse? They have no idea what to do.

At the state level, however, Republican governors and legislators are still in a position to block the act’s expansion of Medicaid, denying health care to millions of vulnerable Americans. And they have seized that opportunity with gusto: Most Republican-controlled states, totaling half the nation, have rejected Medicaid expansion. And it shows. The number of uninsured Americans is dropping much faster in states accepting Medicaid expansion than in states rejecting it.

What’s amazing about this wave of rejection is that it appears to be motivated by pure spite. The federal government is prepared to pay for Medicaid expansion, so it would cost the states nothing, and would, in fact, provide an inflow of dollars. The health economist Jonathan Gruber, one of the principal architects of health reform — and normally a very mild-mannered guy — recently summed it up: The Medicaid-rejection states “are willing to sacrifice billions of dollars of injections into their economy in order to punish poor people. It really is just almost awesome in its evilness.” Indeed.

And while supposed Obamacare horror stories keep on turning out to be false, it’s already quite easy to find examples of people who died because their states refused to expand Medicaid. According to one recent study, the death toll from Medicaid rejection is likely to run between 7,000 and 17,000 Americans each year.

But nobody expects to see a lot of prominent Republicans declaring that rejecting Medicaid expansion is wrong, that caring for Americans in need is more important than scoring political points against the Obama administration. As I said, there’s an extraordinary ugliness of spirit abroad in today’s America, which health reform has brought out into the open.

And that revelation, not reform itself — which is going pretty well — is the real Obamacare nightmare.