It comes as little surprise that a new Hawaii Poll shows waning support for construction of the Thirty Meter Telescope atop Mauna Kea. Two months of expanding protests against TMT appear to have had a powerful effect on public opinion.

About half of all 800 voters surveyed supported TMT, down from 77% 18 months ago, according to results published this week. Notably, about half of all voters also supported the protests, suggesting a deeply rooted empathy for Native Hawaiians peacefully asserting their cultural and spiritual rights.

Whether any of this changes the calculations of Gov. David Ige and TMT’s developers, who so far have been stymied by the blockade of the Mauna Kea Access Road, remains to be seen. The benefits of TMT are indisputable; losing the telescope would have profound effects on the science of astronomy, and on the educational fortunes of countless local students.

Moreover, if the TMT opponents’ tactics prove successful — as they have so far — it could inspire similar actions in unrelated disputes.

On Thursday, protesters opposed to a city parks renovation project at Sherwood Forest blocked the entrance to Waimanalo Bay Beach Park. Honolulu police arrested 28 people and reopened the road to construction vehicles.

Fortunately, like the TMT protests, the demonstrations and arrests in Waimanalo occurred without violence or rancor among those on the scene.

Will future such protests be as peaceful? That also remains to be seen.