The Haitian revolution was a grassroots revolution, started by slaves without any elite support.
They had unusually terrible lives, even for slaves, so nothing to loose. They had a separate culture, religion, language, race which made them completely isolated from the elite group. They also were in the majority by a massive margin.
The revolution spread like a fire. It started at one plantation, news of success got out, the next plantation revolted, and the next, and the next, and so on. After a while, the slaves had congregated to marauding armies that roamed through the land and absorbed supplies and new fighters wherever they went.
The revolution was initially successful, and a moderate government formed. Slavery was a abolished and the government was headed by a black man, but the plantation economy remained in place and the elite remained predominantly white. So it has actually happened once in recorded history.
A counterrevolutionary army was dispatched from France and reconquered the capital. They were soon defeated by a more extreme rebel group, which then committed a terrible genocide. That government was... not a success, to put it mildly.
I don't see how that situation is in the slightest bit similar to modern America. Live needs to be really fucking bad until a grassroots revolt can actually happen.
The last Lord Protector was the guy who had King Charles executed. Not this Charles obviously, the first one in the 17th century.
Cromwell took the title to pretend he wasn't the King of England while he ruled England as King. To be fair, it wasn't all for show, he really did try to get parliament more involved, but every time they did something excessively stupid, he dissolved them.
Charles might wish to act similarly, though I doubt it, but he sure as hell is not bringing that title back.