"If the telescope doesn't get built it will be because the people who want to build it aren't willing to make the compromises that are required as part of a democratic process."
Hawaii doesn't want astronomy, and it is not the job of astronomers to convince them otherwise. Even if they were to start the 7-14 year permitting process over again, it wouldn't change the opposition. Start construction right away at an alternate site.
Sierra San Pedro Mártir in Baja California is a site on the original list for the TMT, but all of the other sites other than Maunakea were in Chile, which is now the location for its southern hemisphere sibling. The TMT needs another northern hemisphere site. Given the current social situation in Mexico, can the safety of construction and operation be assured? If not, I have suggested that qualified site on the Tibetan Plateau, even though it was not on the TMT's original list because that list was composed before China became a partner in TMT. China is one place where the project will be insulated from its real opponents, the Greens.