Biden wants to mandate the vaccine, Fauci wants to give him the justification he needs, that much is clear. Most of the blue states are falling in line, as is the Pentagon and its active troops (99% vaccination rate).
That leaves the red states, with their heavily armed constitution worshiping redneck population. They banned any mandates at state level and refused to enforce it on their national guard units.
This can only end one way, with a civil war. Blue states will force the vaccine on the hold outs, while in red states it will be rejected, but for a few vaccine believers.
So the Pentagon and blue states will invade the red states, and it will be the second US civil war. It's why Biden withdrew the military from Afghanistan, it's the world's most powerful force with 20 years experience in hunting down insurgents, and a huge fleet of extremely capable drones, the most capable weapon system in history.
Unless their goal is to kill everyone with said vaccine injuries. In which case they'll blame them on the unvaccinated and demand they take it. In which case this would move really, really fast.
You know how ineffective this is right?
There's a reason why killers like Stalin don't just go door to door hunting down and killing every poor sod before they starve all of them to death.