William Golding's Lord of the Flies is a novel which is all about power and the struggle to get and keep it.
In the first chapter, the boys who have been stranded on an island by a plane crash hold a meeting, and one of the first things they do is hold an election. Because so many of the boys are younger, they vote based on what they see, and they vote for Ralph.
None of the boys could have found good reason for this; what intelligence had been shown was traceable to Piggy while the most obvious leader was Jack. But there was a stillness about Ralph as he sat that marked him out: there was his size, and attractive appearance; and most obscurely, yet most powerfully, there was the conch. The being that had blown that, had sat waiting for them on the platform with the delicate thing balanced on his knees, was set apart.
It is clear that the conch is a symbol of power, and for most of the novel Ralph is the keeper of the conch and holds some power because of it. Eventually, however, he will be afraid to use the conch because he correctly fears no one will respond.
Jack is the boy who loses the election, and for a time he is content just to be leader of the hunters. Soon, however, he wants more power. He uses the lure of meat to get others to join his tribe, and it works. As time passes, Jack and Ralph are in almost constant conflict. While Ralph is concerned about the good of the group and efforts to get them rescued, Jack is consumed with power and sees Ralph as a threat. Ralph is a threat, not because he wants power but because he is a natural leader and that threatens Jack, who is a weak leader.
Golding eventually refers to Jack not by name but as the chief of the savages, and every boy except for Ralph is in his tribe. That only happens because Jack allows Piggy and the conch to be shattered and because the boys are threatened with violence if they do not comply. When Jack orders his tribe to kill Ralph, he means it. Ralph is the only impediment to Jack's complete control of the island.
Ironically, we have an indication that if the rescue had not happened, Jack's power would have been usurped by Roger, the cruelest boy on the island.