Hawaii is in a unique position because there are still plenty of native Hawaiians around. They arent a native tribe recognized by the U.S. government and some number (most in my mind) dont want to be. Because the overthrow of the last government of the Kingdom of Hawaii was done under shady conditions (basically the sugar barons formed a provisional government and then told the U.S. that they'd like to become a part of the U.S. They did this to join the free trade area that U.S. states enjoy to lower their shipping costs. They had actually tried this once before and then President Grover Cleveland shut them down. He stated that Hawaii had an existing government and seemed to have popular support of the people. But later they tried again and that time the U.S. agreed to annex Hawaii. It was operated essentially as a colony from then on until the 1950's.
So Hawaii is a normal U.S. state. It has state legislation. It obeys federal laws. Except, occasionally native Hawaiians will stand up about some issue. And when that happens, sometimes everyone else will bend toward their perspective. A lot of normal people do so out of respect for native Hawaiians. Politicians do it because it is politically tough to stand in opposition of Hawaiians. As a side note, there are very few republicans in Hawaii. There are none in the state legislature or U.S. representatives. There are a growing number of republicans that grow from the strong military presence.
The thing is, when Hawaiians protest its hard to figure out who or how many they represent. Because there is no official Hawaiian government. (There is the Office of Hawaiian Affairs (OHA). But dont even get me started. lol) So no one can say "Hawaiians dont want the thirty meter telescope (TMT)". You can only say, "those people protesting over there dont want the TMT".
My instinct is that a large amount of this particular protest springs forth from the students of the University of Hawaii. When people started talking about the telescope students started to organize, hold meetings, and invite speakers. At one point the students built an ahu which is a an altar built out of stones right in the main field when you come upon the university, next to the president's office.
The University is probably too scared to remove it. Months later the students planted trees around it. It'll be there forever. Some say that native Hawaiians came to some professors at the University and asked them to help organize but that the core of the anti-telescope movement are native Hawaiians. Its impossible to say. There has never been any kind of survey or vote of native Hawaiians- which itself would be impossible as there is no real registry of native Hawaiians.
This was a long way to say, the only reason this went court was because of protest that, at least in part, included some native Hawaiians. No matter what the court decides, nothing is certain. It could still be slowed for years or indefinitely. If Hawaiians block the one road up the mountain, and are willing to get arrested on a daily basis, its hard to imagine that any politician would back the continued construction.