Why did some Americans think the United States should take control of Hawaii?

There were at least three major reasons for wanting to
take control of the Hawaiian Islands in the late
1800s.

First, there was the desire for military power. 
This was the age of Alfred Thayer Mahan and the idea that naval bases were the way to
project power over long distances.  Many Americans felt that a base in the Hawaiian
Islands would help give the US control of the central
Pacific.

Second, there was the desire for economic power. 
There were many Americans who wanted the resources of the Hawaiian Islands.  At this
time, sugar was the major product of the islands and Americans wanted control of that
resource.

Finally, there was competition with other
powers.  There was concern, for example, that the British would take the islands if the
US did not.  This would give the British the sugar as well as a base for their navy. 
This would enlarge the power of the British Empire instead of helping the US gain
power.