In 2017, when consumer confidence was strong, San Geronimo Valley residents approved a special tax to support local schools by a comfortable margin. This year, with concerns about tariffs and inflation running high, the prospect of renewing the tax appears less certain. Nevertheless, Kathleen Graham, the Lagunitas School District superintendent, remains hopeful that voters will come through. “It’s critical to our program,” she said. “I’ll start sleeping after it passes.” Measure A, an $850 per…