When we acknowledge that Jesus is our King, we imply that we are His subjects. It is so difficult for us to be subjects, for when we pray "Thy kingdom come," that means His will, not ours, is to be done (Mt 6:10). When we enthrone Jesus as our King, we must necessarily dethrone ourselves.
It is even more challenging for a citizen of the USA to be a subject. Our country is founded on the rejection of subjection to the King of England. Many people have come to the USA to escape from being subjected to kings. Our form of government is an alternative to being subjected to kings. We have made a "declaration of independence" from subjection to kings.
Moreover, if we subject ourselves to King Jesus, we subject ourselves to a crucified King. If a king made us prosperous and victorious, we may be able to tolerate being his subjects. But why would we accept a King Who wouldn't protect us from suffering and death? A crucified King probably would not make it a priority to preserve the American lifestyle. He could "ruin everything." If Jesus insisted on being our King, and we insisted upon preserving our own independence, we probably would have no alternative but to crucify Him.
What will you do with Christ the King? Will you sneer (Lk 23:35) and jeer at Him (Lk 23:36) or fear and draw near Him? Will you revile Him (Lk 23:39) or subject yourself to Him?