As President Trump begins to more openly advocate for rescinding measures aimed at limiting the spread of the novel coronavirus in the country, it has revealed a pervasive, incorrect understanding of the virus’s risks. You can see it in Trump’s tweet from Tuesday morning.

It’s the seniors who need protection, Trump claims, allowing us to segment those people out so the rest of us can carry on as usual.

The result? Arguments like this one from Texas Lt. Gov. Dan Patrick (R) on Fox News Channel on Monday night.

“No one reached out to me and said, ‘As a senior citizen, are you willing to take a chance on your survival in exchange for keeping the America that all America loves for your children and grandchildren?’ ” Patrick said. “And if that’s the exchange, I’m all in. And that doesn’t make me noble or brave or anything like that. … My message is that let’s get back to work. Let’s get back to living. Let’s be smart about it. And those of us who are 70-plus, we’ll take care of ourselves, but don’t sacrifice the country.”

If the economy is on hold simply to protect people in their 70s, Patrick is saying, it’s not worth it. A similar sentiment seems to be undergirding the decision by Trump ally Jerry Falwell Jr. to reopen Liberty University to students. After all, if the threat is mostly to older Americans, why not let college students go about their daily lives?

Why not? Three reasons. First, it isn’t only older Americans who will die of covid-19, the disease caused by the novel coronavirus. Second, allowing the virus to spread even among lower-risk groups puts more vulnerable populations at risk. Third, even among those at lower risk of dying, the personal and local effects of the virus can be significant.

That first point it the most important. The Kaiser Family Foundation estimated earlier this month that 106 million Americans are at heightened risk from the virus. More than a quarter of those are people younger than 60, people who have known medical conditions that might make them more susceptible to damage from covid-19.

The Centers for Disease Control and Prevention released an analysis of coronavirus cases from mid-February to mid-March showing that, in fact, the highest risk of death was for those age 65 and older. As the level of impact increases as the circles below grow smaller, you can see how the share of the circle occupied by older patients, demarcated by a white line, increases. (The circles themselves are not to scale relative to the number of actual cases.)

But you can also see that people younger than 45 remain at risk of needing hospitalization. A fifth of those who needed to be hospitalized were ages 20 to 44 in the CDC’s analysis. Almost 40 percent were ages 20 to 54.

The good news on which so much of this hinges is that younger people are less likely to have significant problems. But if you allow the number of people in that less-at-risk age group who contract the virus to increase significantly, you will similarly see a surge in the number of people needing hospitalizations.

Between 14 and 21 percent of those in the 20-to-44 age group might require hospitalization for covid-19, according to the CDC’s analysis. Lower than the rate for the oldest age group, with a far lower likelihood of dying.

If the number of coronavirus infections is allowed to increase with fewer controls within that age group, though, hospitals will probably still experience significant strain. That strain puts everyone at risk, as hospitals have to balance numerous covid-19 patients with people needing other care. Some of those needing other care, of course, will be the elderly people who are most at risk.

It’s hard to see how older Americans could be sufficiently isolated from risk as the economy moves on as normal around them and younger people are more likely to be exposed to the virus. Preventing family visits is one thing, but how would one prevent staff members at nursing homes from being exposed to the virus if they are less restricted as the economic shutdown loosens? The direct implication of Trump’s suggestion is that we accept a broader spread of the virus so we can return to normal. It’s an assumption that we can contain the virus in at least some way, an assumption that we’ve already seen disproved.

But, again, it’s not as though a younger person getting sick with the virus is simply going to go about his or her life as usual. ProPublica spoke with a respiratory therapist in Louisiana, who described his surprise at the effect the disease can have even on people younger than 60.

“I have patients in their early 40s and, yeah, I was kind of shocked,” he said. “I’m seeing people who look relatively healthy with a minimal health history, and they are completely wiped out, like they’ve been hit by a truck. This is knocking out what should be perfectly fit, healthy people. Patients will be on minimal support, on a little bit of oxygen, and then all of a sudden, they go into complete respiratory arrest, shut down and can’t breathe at all.”

That article is now the most-read in the news organization’s history. Hopefully some of those reading it work at the White House.