Six justices heard arguments Wednesday on a Nevada Policy Research Institute claim that the Regional Debt Management Commission violated state open meetings law by not taking public comment before approving the measure for the ballot.
The court session was technically a settlement conference, and justices didn't issue an immediate decision.
NPRI is appealing Clark County District Court Judge Valorie Vega's ruling that the commission action caused no harm.
Officials say the tax would collect about $74 a year for each $100,000 of assessed home value in the Clark County School District.
District officials say the money would build and renovate schools and buy new equipment.