Sen. Ted Cruz (R-Tex.) offered a smug prediction four months ago. Those efforts to contain the coronavirus that has now killed more than 250,000 in the United States? Just political opportunism, he said.

“If it ends up that [Democratic presidential candidate Joe] Biden wins in November — I hope he doesn’t, I don’t think he will, but if he does, I guarantee you the week after the election, suddenly all those Democratic governors, all of those Democratic mayors will say, ‘Everything’s magically better. Go back to work, go back to school. Suddenly the problems are solved,’ ” Cruz said during a television interview. “You won’t to have to wait for Biden to be sworn in. All they’ll need is Election Day and suddenly their willingness to just destroy people’s lives and livelihoods, they will have accomplished their task.”

“That’s wrong, it’s cynical and we shouldn’t be a part of it,” he added.

He wasn’t alone in that prediction. President Trump repeatedly made a similar claim. In an all-caps tweet on Oct. 27, for example, Trump insisted that “ON NOVEMBER 4th” — the day after the election — “YOU WON’T BE HEARING SO MUCH ABOUT IT ANYMORE.”

At a campaign rally a few days later, he made the same claim.

“On November 4, the day after, they’re going to say, ‘All right, we’ll open up now,’ ” Trump said. “That’s why they’re locking down. But we’re going to have a safe vaccine that ends the pandemic. Without it … it’s rounding the turn. Because all they want to do, you turn and then there’s covid, covid, covid, covid, covid. We’d like to talk about covid, and then, next turn. Here’s what happens, November 4, you won’t hear too much about it. You won’t hear too much about it.”

On July 22, when Cruz offered his assessment, the country was near the peak of its second surge in new coronavirus infections. Over the preceding week, the country had averaged more than 43,000 new cases each day, despite Vice President Pence claiming the previous month that no second wave was imminent.

When Trump was speaking at the end of October, the situation was already far more dire. On Oct. 27, the date of his tweet, the seven-day average of new cases was nearly 72,600. By Nov. 1, it was past 82,000. Anthony S. Fauci, the country’s top infectious-disease expert, had warned that the country might pass 100,000 cases a day if the pandemic wasn’t contained during that second surge. Now in the third surge, which began about Sept. 12, the country has been averaging more than 100,000 cases a day for more than two weeks.

In the wake of the election, Democratic governors and mayors didn’t scale back containment efforts. For one thing, there weren’t many such efforts in place; in New York, for example, businesses were open. People were going to the gym and dining in restaurants, and their kids were in school. But the more important factor was that the new surge was already underway.

As of writing, the number of new cases being recorded each day on average is nearly five times the rate on Sept. 12. Since Nov. 3, three weeks ago, it has nearly doubled.

That’s not just a function of more testing. The rate of positive tests has climbed to nearly 10 percent, from 4.4 percent, on Sept. 12, and 6.8 percent on Election Day, according to data from the COVID Tracking Project. More tests — but more tests coming back positive. One glimmer of good news is that the rate appears to be declining slightly.

But that masks a broader concern. The number of new cases is a leading indicator of new hospitalizations and eventual deaths. Both of those metrics are on the increase, with the number of people currently hospitalized now 69 percent higher than it was on Nov. 3. The average number of deaths each day is 61 percent higher than on Election Day.

As we’ve pointed out, there’s a fairly steady relationship between the number of new cases and the number of new deaths. Since Aug. 1, the number of deaths on a given day has consistently been about 1.7 percent of the new cases two weeks prior. That average is down slightly from a month ago and the figure since Election Day has been about 1.4 percent — although it was similarly lower shortly before the peak in deaths this summer. The implication, though, is unavoidable: By early December, the country probably will have 2,400 to 3,000 deaths per day.

That’s higher than the peak the country had in the spring.

This recent increase has meant not only that the Cruz-Trump prediction was wrong, but that even Republican officials skeptical of imposing restrictions have decided to implement new guidelines aimed at stopping the virus’s spread.

Slowing the spread will be trickier because of the Thanksgiving holiday. On Sunday, air travel was at 45 percent of the volume seen on the equivalent weekday a year ago, according to TSA data — the highest level since March 16. Fauci has urged Americans to rethink their plans for the holiday so as to not pour gasoline on the already raging fire.

A study from the Centers for Disease Control and Prevention found that 60 percent of new coronavirus infections come from people either not yet showing symptoms or who would not show symptoms at any point in their illness. Testing won’t necessarily provide clarity on whether someone is infectious, meaning that many of those who participate in group dinners Thursday may be contagious and not know it. Hence Fauci’s concern.

Cruz, ever concerned about political actors using coronavirus for cynical purposes, offered a related tweet over the weekend.

If there’s one thing he’s proved, it’s that his assessments of the risks of the virus can be trusted.