Dr. Anthony Fauci has been making the rounds on public affairs programs for several days talking up vaccination requirements for domestic travel. He emphasizes in each case that it makes sense for international travel to keep virus cases out of the country (but unvaccinated Americans are allowed to return, and the virus is already spreading here rapidly).
Fauci then goes on to suggest that a domestic vaccine travel requirement would make sense, not to ‘keep the virus out’, but to serve as an incentive to get vaccinated. In addition to being legally questionable, it may wind up having the opposite effect Fauci hopes.