Why do the group not vote against Jack as a leader?

The group's dissention illustrates the widening gap between the civilized and uncivilized. The group doesn't vote against Jack because at this point, he is the physically stronger leader.... he is also providing food. Let's face it, food is a huge issue when you're stranded on an island. Note, fear of physical violence also plays a part. The boy are also afraid of what Jack might do to them.