Why is Ralph considering giving up leadership?

Ralph called a meeting in chapter 5 with the intention of ending the discussion of the beast once and for all. Unfortunately his plan backfired and instead of persuading the boys that the beast wasn't real they ended up voting in favour of a belief in ghosts. The meeting descended into choas with most of the boys running onto the beach to perform a 'pig dance.' Totally disillusioned by the way the meeting had gone and the outcome of the vote Ralph wondered why he was even bothering to try and lead the boys, when they no longer behaved rationally and he seriously doubted how much control he even held over them.