(AP) — Hundreds of millions of tax dollars for public schools are at stake in a lawsuit before the Kansas Supreme Court, but so is the core of Republican Gov. Sam Brownback’s vision for the state.

Brownback banks on massive personal income tax cuts boosting the state’s economy. His successful push for the reductions makes Kansas a lab for conservative ideas.

But Brownback’s signature policy stands to unravel if aggrieved school districts and students pursuing the lawsuit succeed in forcing a dramatic increase in education spending.

A lower-court ruling said Kansas must increase annual aid to its public schools by at least $440 million. Projections from the Legislature’s research staff suggest that the state can’t add so much new spending to its annual budgets with the income tax cuts in place.