It's not surprising that polls have changed.  Initially, there was talk that the telescope was only paying $1 a year in rent, which created a sense that Hawaiians were being taken advantage of.   It took some time for the news to get out that the TMT has actually paid hundreds of thousands of dollars already and will be paying slightly over $1 million every year for most of the time it's in operation.  

http://hawaiitribune-herald.com/news/local-news/oha-funds-tmt-lease-holding