Juliette Kayyem, assistant secretary for homeland security under President Obama, writing for The Atlantic:
The White House has rejected a nationwide vaccine mandate—a sweeping suggestion that the Biden administration could not easily enact if it wanted to—but a no-fly list for unvaccinated adults is an obvious step that the federal government should take. It will help limit the risk of transmission at destinations where unvaccinated people travel—and, by setting norms that restrict certain privileges to vaccinated people, will also help raise the stagnant vaccination rates that are keeping both the economy and society from fully recovering.
Flying is not a right, and the case for restricting it to vaccinated people is straightforward: The federal government is the sole entity that can regulate the terms and conditions of airline safety. And although air-filtration systems and mask requirements make transmission of the coronavirus unlikely during any given passenger flight, infected people can spread it when they leave the airport and take off their mask.