If we're thinking of the same poll, it was conducted in 2015 and the polling was backed by Caltech, who has a vested interest in TMT and neither the instrument or the raw data were available for other researchers to analyze.
An independent poll conducted by the Honolulu Star-Advertiser in 2018 found that 72 percent of Native Hawaiians (registered voters) support TMT, 23 percent oppose it and 5 percent were undecided.