Will Republicans once again nominate Donald Trump for president? Or will they turn to Ron DeSantis instead? I have no idea.

What I do know is that anyone imagining the Florida governor as a more sensible, saner figure than Trump — a right-wing populist without the reality-denying paranoia — is delusional. DeSantis hasn’t gone down all the same rabbit holes as Trump, but he has gone down some of his own, and his descent has been just as deep.

Above all, DeSantis is increasingly making himself the face of vaccine conspiracy theories, which have turned a medical miracle into a source of bitter partisan division and have contributed to thousands of unnecessary deaths.

Let’s back up and talk about the story of COVID-19 vaccines so far.

In spring 2020, the U.S. government initiated Operation Warp Speed, a public-private partnership intended to develop effective vaccines against the coronavirus as quickly as possible. The effort succeeded: By December 2020, far sooner than almost anyone had imagined possible, vaccinations were underway. (I received my first shot the next month, on Jan. 28, 2021.) And yes, this was a success for the Trump administration.

Have the vaccines worked? And how. There are multiple ways to evaluate their lifesaving effect, but I’m especially taken with a simple approach promoted by analyst Charles Gaba, who looks at the correlation across U.S. counties between vaccination rates and COVID death rates. Between May 2021, when two-dose vaccinations first became widespread, and September, the least-vaccinated 10% of counties suffered a death rate more than three times as high as the most-vaccinated.

Now, you may have heard that at this point, deaths among vaccinated Americans are exceeding those among the unvaccinated, which is true. But that’s partly because most deaths are among the elderly, who are overwhelmingly vaccinated; very few Americans have received no shots; and not enough vaccinated people are getting booster shots.

But why are some U.S. counties so much less vaccinated than others? The answer, as Gaba shows, is partisanship: There’s a startlingly close relationship between the share of a county’s voters who supported Trump in 2020 and the percentage of that county’s residents who haven’t received their shots — and the percentage who have died from COVID.

You can, by the way, see the same patterns at the level of whole states. For example, although New York was hit hard in the first months of the pandemic (before we knew how the coronavirus spread or what precautions to take), since May 2021 more than twice as many people have died of COVID in Florida than in New York. Even taking Florida’s slightly larger and much older population into account, that’s thousands of excess deaths in the Sunshine State.

Yet why should vaccination be a partisan issue?

Right-wing opposition to lockdowns and social distancing in the early stages of the pandemic made at least some sense, since these public health measures involved requiring that people make some sacrifices to protect other people’s lives. Even mask mandates required accepting a bit of inconvenience, at least partly for the sake of others.

But getting vaccinated is mainly about protecting yourself. Why wouldn’t you want to do that?

The immediate answer is the widespread belief on the right that the vaccines have terrible side effects. This belief is hard to justify: If it were true, shouldn’t there be a lot of evidence for such claims, given that more than 13 billion doses have been administered worldwide?

Ah, but the usual suspects claim that sinister elites are suppressing the evidence. Which brings us back to DeSantis, who announced Tuesday that he was forming a state committee to counter federal health policy recommendations — and asking for a grand jury investigation into unspecified “crimes and misdemeanors” related to coronavirus vaccines.

OK, I doubt that anyone believes that DeSantis knows or cares about the scientific evidence here. What he’s doing instead is catering to a Republican base that equates listening to experts, on public health or anything else, with “wokeness,” and demonizes anyone saying things it doesn’t want to hear.

As far as I can tell, DeSantis hasn’t joined the likes of Elon Musk in calling for the prosecution of Anthony Fauci, who led America’s COVID response. But he has called Fauci a “little elf” and said that we should “chuck him across the Potomac.” (Presidential!)

Now, will DeSantis’ attempt to position himself as the leader of the anti-vax movement and give at least tacit approval to conspiracy theories actually endear him to the Republican base? Again, I don’t know. Even if it does, I suspect that it will hurt him in the general election if he does become the nominee: Vaccine paranoia and Fauci hatred are still niche positions in the electorate at large.

But anyone who imagines that replacing Trump with DeSantis as the GOP’s leader would signal a party on its way to becoming sane again is in for a rude shock.

Paul Krugman is a New York Times columnist.