The Covid pandemic dominated the last years of Donald Trump’s presidency, and the discontent it caused most likely contributed to his loss in 2020. But on the campaign trail this year, Mr. Trump rarely talks in depth about public health, dwelling instead on immigration, the economy and his grievances.

Still, Project 2025, the blueprint for a new Republican administration shaped by many former Trump staff members, lays out momentous changes to the Food and Drug Administration, the Centers for Disease Control and Prevention, and the National Institutes of Health.

And Mr. Trump’s embrace of Robert F. Kennedy Jr., a vaccine skeptic, and his campaign slogan, “Make America Healthy Again,” suggests there will be significant changes to the nation’s public health priorities should Mr. Trump regain the presidency.

“I’m going to let him go wild on health,” Mr. Trump said of Mr. Kennedy at a rally in New York City on Sunday. “I’m going to let him go wild on the food. I’m going to let him go wild on medicines.”

Republican critics increasingly describe the health agencies as corrupt, riddled with conflicts of interest and staffed by myopic bureaucrats accountable to no one.

Mr. Trump echoed these themes at a rally in Wisconsin: “We’ll take on the corruption at the F.D.A., the C.D.C., World Health Organization and other institutions of public health that have dominated, and really are dominated by corporate power, and dominated really by China.”