This varies among states, ranging from 8.5% of the population in Hawaii to 100% of the population in Washington, D.C. Water fluoridation is not mandatory, and while there is a recommended fluoride concentration in drinking water (0.7 milligrams per liter ...

Florida's surgeon general, Dr. Joseph Ladapo, cited developmental concerns from higher levels of fluoride than are found in most U.S. water supplies.

The Washington Post and other media noted that medical organizations responded by calling Kennedy’s assertions unfounded at the levels of fluoridation used in drinking water. But many of them have also noted that in an NBC interview, Trump said possible action against fluoridation of water “sounds OK to me ... You know, it’s possible.”