So many of his supporters are dying off in states with very high vaccination rates, and he probably finally put the numbers together. There was great data lining up COVID reported deaths with counties with a high GOP vote in 2020, and the data correlated. At some time, someone internally must have told him, you are killing your base off unless you do something. Kaiser Family Fund showed the rate of Republican Covid vaccination has plateaued at 59% while 91% of Democrats have been vaccinated--hospitals with COVID wards are predominately filled with unvaccinated (though not all unvaccinated and not all GOP base, some vaccine hesitancy considerably in poor black rural America as well). Nice for him to think of himself first.
Shepherds love people like you.