With Proposition 30, Governor Jerry Brown is asking California voters to back an increase in sales and income taxes to support education and public safety. This year’s state budget depends on the money from this proposition. Supporters say well-off Californians should give more to sustain public schools. But critics say the measure is a large tax increase which would hurt the state’s economy and business climate. And backers of a rival tax initiative — Prop. 38 — say Prop. 30 doesn’t guarantee new money for education beyond existing general fund spending.