When the Moralist Military Dictator Oliver Cromwell plotted not just the annihilation of the Irish, the migration of the Jews to the emptied Emerald Isle, along with the shuttering of gambling houses, the stifling of free speech, and martial law throughout Great Britain, his erstwhile supporters could think only one way to curb his power:
Crown him King of England, and establish another royal dynasty styled the House of Cromwell. The visionary tyrant summarily refused the backhanded compliment.
An ironic turn to modern democratic sympathies, a king's divine right was intended to curb the power of the monarch, tying his leadership to people, the land, the culture, and the historical identity of the people.
In the First Book of Kings, the Israelites repudiated the leadership of the the final judge, Samuel, demanding instead a King, one who would fight their battles for them.
In Ancient Times, Julius Caesar refused to be crowned king, preferring to rule as Perpetual General Consul.
In the Gospel of John, when the crowds contemplating making Jesus a king, a military leader who would always provided them bread (and perhaps circuses), Jesus fled.
For whatever long-range purpose, crowds seek to create a king to supply their needs (at the expense of others), controlling one man to meet the needs of the many. Hardly a promotion to absolute power, but a royal flourish to enslave a man to the will of the people.
Modern Dictators wish to sweep away the past, recreate reality, and define power in terms of their arbitrary will. A king, even to have authority, must resort to his status as a leader in a lineage and a legacy, all of which bind him to the people and the land, no matter how poorly he may serve them, or how self-serving he may be.
For this reasons, Cromwell's supporters proffered a crown, to keep Cromwell from wreaking havoc on the English countryside, its people, and their posterity, including their legacy of civil right.